From what I understand the American distributor tried to sell Summer with Monika as a sex film and shot new footage to exploit his wishes. This is the only possible reason I can think of to explain extra footage.
@Pisces Rising Funny that you mention it, but I don’t seem to recall those two shots you show there. I just watched it recently within the last week or so. I remember seeing her nude from behind. I can’t remember if she was shown from the front as well. I don’t think so, though, but I could be mistaken.
These are production stills, i.e. photographs from the set. Why would they be in the film?