In the press conference (at about 44:20) of World Chess Championship, Maurice Ashley invites Nepo and Carlsen to take a photo with the trophy but Carlsen says that he finds it inappropriate. Why is that?
He probably doesn't like that guy who told him to take photo which was pretty clear in the interview once in the past when Carlsen got angry on him for no apparent reason. Also Maurice works for chess.com that Carlsen apparently doesn't like too much neither. Maybe Carlsen doesn't like to be pushed around for someone to make a "cool" Instagram like photo. The most important reason though IMO would be that based on football (I don't know too much about other sports) they never make pictures in front of a trophy unless they're winners who already won it. Before the competition begins they either Photoshop the trophy somewhere in the promotional materials or like in the finals you can see players only walk next to the trophy before the match. Only the winner gets to be photographed posing with the trophy I believe at least in football that Carlsen is a fan of so he might think similar. He also is very experienced in many chess ceremonies so it might look the same in chess then.