They seem to be wearing the same tie and some kind of uniform. It is a bit odd actually unless it is indeed some uniform thing.
It is not positive either that Christian is being photographed next to a friend holding a cigarette and that there is again a glass of something alcoholic on the table. I know what some people will say about teens in Europe and their drinking or smoking habits, but still it's bad optics in my opinion.
I am not sure if I sympathize with this new "posh" Christian either. He seems to be photographed now always wearing a jacket and more formal clothes (shirt, shoes, etc.) and always hanging out in fancy places. Ok, he is a prince with upper-class friends, but, I don't know, we often see other royals in Europe in much more casual settings and Christian himself seemed to be more causal (before he joined his current social clique perhaps?).
EDIT: I noticed now that Muhler said it's probably a graduation party, which makes sense in hindsight, so I withdraw some of my criticism. Also, it looks that those pictures were not meant to be public if I understood it correctly.
Unfortunately you have a point.
That could potentially turn out to become a PR problem for Christian.
That is that he seen hanging out a lot with upper-class friends who are dressing conservative. And also hanging out with the European jetset.
There is a conservative almost ultra liberal trend in the high schools these years, especially among young men.
I personally prefer the young to be a little rebellious and wanting to change the world and do things differently. It's healthier that way. - And they'll turn more conservative later on alright when they settle down.

So it makes me uneasy when I see young people dressing conservative, or even worse: dressing up in uniforms in whatever form they may take.
I say this as a liberal who politically has never been further left than the Social Democrats.
Anyway, if Christian does not focus on issues that concern ordinary people and actually take a genuine and keen interest in that, it may turn into a problem where Christian is seen as elitist.
That of course is a pessimistic view and as Prinsara pointed out Christian is hardly expected to dress like a prole (in DK we may say a Christianit, but that would require a long explanation) and it looks to me that this party had a theme, a 20s theme perhaps judging from the feather and headband worn by the young lady next to Christian.
I think it will be healthy for Christian to join the military and meet determined people from all parts of DK and with all sorts of backgrounds.
All are equals in the mud on a cold Novermber morning in the rain with blisters on the feet...
And I also think it would be very healthy for Christian to study in Australia. I think we can rely on the Australians to cut him down a bit if need be. ?