I don't use Snapchat or VR and even I am more interested in the filters. They are funny and the friction to try it out is literally zero. The tech itself is cool as well.
Aren't they? I didn't have a mac a decade ago, and I never really used photo booth since I got one anyway.
But I think snapchat has face-altering features as in 3D modifications while photo booth only changed the image itself or maybe identified "head is at x,y" at most.
Snapchat can modify your head, make interactive animations and all that jazz. Do note that I never really used snapchat, but these are my impressions from the few times someone pointed it at me.