What is this in-game artwork of Monokuma referencing?
I believe it may be a monokuma version of the official 'Danganronpa Girls' / 'Danganronpa Boys' artworks





I'm not sure if the offical-ness of the male version, but both seem to have the characters bunched up on one side, with some small effect in front of them. In the monokuma version, this is replaced with blood.