At this point, a bystander spoke up. Was he sure he wanted to take part in the exhibit? After all, his government had not yet ratified the treaties that the exhibition was promoting. Yes, he said - he still wanted to have his picture taken.
It's not an everyday occurrence for a museum, but the peace centre is not concerned with everyday subjects. The first woman to become a peace prize laureate was Bertha von Suttner, who won the award in 1905, four years after the first award. The summary of a recent show on von Suttner claimed: 'Peace work is as controversial today as it was 100 years ago.' In unexpected ways, the centre - which attracted 100,000 visitors in its first year and is currently braced for the flurry of activity that will follow this month's announcement of the 2006 peace prize winner - shows just that.
'An art exhibition is one thing, and politics is something else. This is something in-between,' says the director of the centre, Bente Erichsen, formerly a film-maker and then director of two theatres before her current job.
'It's like being the director of a theatre,' she adds, describing her regular meetings with the centre's project manager to assess the many applications the centre receives from organisations wanting to exhibit. 'You have to choose what you think is very interesting, touching, and what people can learn from - the important issues.'
The centre is part-museum and part-showcase for the peace laureates nominated each year by the Nobel Committee. The Nobel Foundation, which is also based in Oslo, came up with the idea for the venue, but does not fund it (there is a Nobel Museum covering all the awards the foundation gives, in Stockholm, Sweden). The centre treads unusual ground, celebrating the history of the peace prize, but veering inevitably into contemporary politics.
The exhibition for last year's laureate, Mohamed ElBaradei - rewarded jointly with the International Atomic Energy Agency (IAEA), which he heads - was nothing if not topical. It ran until 13 April and went to the heart of the Iranian nuclear dispute, which has exercised diplomats throughout this year, while North Korea's missiles have also made made regular headlines.
The exhibition space is in the former international press centre in a listed building that was originally a railway terminal - its brown walnut wood planks for walls are part of the British architect David Adjaye's radical interior design.
Occupying the first-floor exhibition space, the ElBaradei show offered a photographic day-in-the-life of the laureate and his bodyguard. Alongside, there was a succinct overview of the issues surrounding the IAEA's work promoting peaceful uses of nuclear power.
ElBaradei and the IAEA received the award, in the words of the committee, 'for their efforts to prevent nuclear energy from being used for military purposes and to ensure that nuclear energy for peaceful purposes is used in the safest possible way'. But the exhibition did not ignore the ethical flipside. There were also pictures of Greenpeace anti-nuclear activists protesting against the awarding of the prize to ElBaradei.
'We promote the laureates' work, even when they are controversial,' explains the centre's information officer, Kirsti Svenning. 'ElBaradei himself is a controversial man. We have to find a balance so as not to offend anyone too much. You try to keep a bit of an edge, but you don't want to scare off the general audience.'
Despite her artistic background, the director Erichsen has embraced the political side of the centre's activities, which also involve regular film screenings and talks. 'When we did the Amnesty exhibition on arms control, it was before our government said yes to the arms trade treaty,' Erichsen says. 'They have [backed the treaty] now. Not because of us, it was because of Amnesty. But for us it was important to give a signal that this was a case we would very much like to make people conscious of.'
With its politically sensitive subject matter, the centre knows how to win the attention of Norway's government. 'The ministry of foreign affairs likes to present us to its guests,' she says. She explains that this has included mixing Begum Sehba Musharraf (the wife of Pakistani president General Pervez Musharraf) with the Dalai Lama, for example.
'There has to be some personal opinion behind everything that's done here,' Erichsen adds. 'It's important that we're not a kind of official, political voice from the ministry of foreign affairs. We can be critical of anything.'
The centre gives the visitor a lot to think about, partly through the subjects it addresses, such as child soldiers, and partly through technology. Last winter, the large flexible space on the ground floor was filled with the installation Triptych of Hope, a set of three great, circular plastic enclosures that looked like a piece of video art. Inside, videos of different aspects of war, peace and tyranny were projected on to the walls.
The first part, focusing on the hopelessness of it all, had a brutal soundscape of wailing and constant white noise of the type used in some countries as a torture tool; the third part, where the focus was on hope, had projections of butterflies and ethereal chanting piped in - amid projected quotations from sources as diverse as Mao and the Declaration of Human Rights. All the historic content in the piece was checked by historians from the Nobel Institute- an essential step given the sensitive subjects of the exhibitions.
Politics has again raised its head. The centre's 2006 autumn programme features work by the Iranian photographer Abbas focusing on Islam, Judaism and Christianity. This will be followed by a show starting on 1 December of war photography by James Nachtwey, who will also create the photographic exhibition on this month's new laureate, which will open in December. Erichsen also hopes to host work by another Iranian artist, the New York-based Shirin Neshat.
In between arranging these international shows, she jets off to visit other European museums, and admits to having been particularly impressed by the Jewish Museum in Berlin. She has sought advice from representatives of other Norwegian museums, but the centre, still in its infancy, has not yet forged formal relationships with many institutions.
Based entirely on graphic, photographic and text content, the centre does not have its own collection of artefacts. Instead, it has worked hard to find hi-tech and dynamic ways to present the static information on past laureates and their achievements.
The centrepiece is the Nobel Field - a darkened room filled with a field of glowing, fibre-optic stalks interspersed with a hundred waist-high liquid-crystal screens on metal stalks: the monitors bear photographs of the laureates and automatically display text content when the visitor approaches.
The technology (designed by the American-based Small Design Firm) is followed in the next room, the Nobel Chamber, by a virtual book with projections of content on the Nobel Foundation's founder Alfred Nobel's life appearing on the pages as they are turned. The final stage is the Wall Papers, a grid of computer screens with thousands of articles on the historyof Nobel peace laureates.
Adjaye's design and the stylish photography in the ElBaradei show mean that parts of the centre verge on gallery territory. A feature that greets you as you pass from the shop to the first ground-floor space consists of a video of the award announcement playing at the end of a space lined with panels of burnished metal. Closer inspection reveals that this is supposed to evoke the texture of the Peace Prize medal itself.
A few weeks after the minister visited Oslo, Spain backed Amnesty's treaty to control the trade in small arms. Was his sign-up in the Nobel Peace Centre a statement of intent? Whatever the answer, when foreign lawmakers are faced with exhibitions on such politically difficult issues, Svenning says 'it does get some interesting results'. With diplomats working frantically this summer as more rockets fell in the Middle East, the role of the centre became even more interesting.
'Our mission is not to work for peace in the political sense,' Erichsen says. 'We're not a political organisation. But if we can make people think or act individually, I think that's enough.'
Roland Lloyd Parry is a freelance journalist based in Paris