Ha, I never knew that Kirk Cameron had been a child star (I never saw Growing Pains). I love some of his recent stuff, so I think of him as more of a small time, recent actor because I didn't realize he'd done big stuff as a kid. Funny how differently people can look at things, based on what they are aware of.
I don't think it's so much the small cake or the simplicity of the party items as it is the two women standing *far* back and looking somewhat morose. The woman to the left looks like she's standing *behind* some boxes... am I misinterpreting that? And the other woman being out the doorway. The fact that the two people in the picture are standing so far back, and that apparently there were others at the party who are standing behind the camera, makes me think that this photo was meant to, for whatever reason, *just* show Cameron, and either it was an "oops," the cameraman figured on just cropping it later, or maybe Cameron started to blow out the candles before the shot was set up completely and so he just snapped, or something. Otherwise I can't imagine why the women are so far away from him.
Also, the size and number of those sandwiches to me definitely makes clear that there are others who are at the party and aren't pictured. Otherwise that's a lot of food for four people, at most two of whom are adult men.