Tim is a child and now he's a buff adult in the span of a few months our time. Crazy
From a recent CBR article on Red Robin: "For some reason, when I started doing the book, I had some difficulties drawing Robin without making him look an adult like Batman, because in the series he's 'doing what Batman does,'" [Ramon] Bachs told CBR. "But step by step, I've been able to make him look like a believable teenager. His suit reminds you of Batman's, in a certain way, and the cape makes it even more similar. The readers will be the judges, I guess."