Doesn't matter what the company calls themselves, it's a forum that people upload phone pics to and those photos/images are then displayed in an algorithmic form (used to be chronological with forums)... same as a forum!
Remember, Google is an advertising company but they'd consider themselves more of an engineering or search company... doesn't mean they're right!
Edit: Forgot to ask, how do Snapchat make their money? Is it all through advertising? It's a genuine question, I don't use it and have no idea! If it's all advertising revenue then they're an advertising company like Google and Facebook!