Ok, somebody posts a screenshot of a film, when somebody guesses the film he can post another. Easy enough. Hints can be given if nobody seems to get it; maybe an extra screenshot or director/actor names etc. Let me start this off:
If you are really sure you can post the next screenshot, it keeps the pace of the game up since the one posting it isn't here 24/7. If you got it wrong after all it doesn't really matter anyway, we can guess 2 at a time then.