Billy Goat
WKR
I had read about something similar happening with ducks. Guys had their birds lined up on the tailgate for a picture and were cited for not seperating their limits. To me its not worth the risk because if a game warden cites you (even if he is in the wrong) then you have to go to court to prove your innocence.
It's not a party limit, only way pile pictures are legal is if they are tagged by individual hunters. Colored zip ties work.
That's federal, not different state to state, however probably only a fed warden would cite you for it.