That's what's known as a "high-concept pitch." It gives people a broad idea of what the thing is about and gets people excited by connecting it to something that's already well-loved, but often belies the actual details and intentions behind the thing. The bigger and more iconic the comparison, the more smoke and mirrors are likely being used.

For example, "Inception" could be pitched as "Like 'Ocean's Eleven' meets 'The Matrix'". It's not inaccurate, but all it's actually meant to convey is "It's a heist movie with trippy visuals." If you go into the theater expecting either of those movies, you're probably going to be a little bit confused.