I've seen it on quite a few movies where they show pictures of the family in some past gathering or with friends but usually they are photoshopped in some background or their faces are shopped onto someone's elses body and not that well made.
If you asked me what movies I woudln't remember but I've seen it more than 3 times, usually in comedies. I don't think it's for comedic purposes because that would sort of be a 4th wall joke. And I'm sure for the budget of a semi big Hollywood movie they would at least get someone who is good at Photoshop.
Why does it look like that?