Congratulations! You're an artist!

No, you can't really say it like that in English. First, it's just "congratulations" or "congrats" for short. There are even more words, but "congratulations" is fine. Then instead of "you do art!", you can phrase it in different ways. "What a great piece of art(work)!", "so artistic!", "what a great photo!", "you're such a great artist!", and so on. There's lots of different ways you could phrase it. While you could even say something like "now that is a brilliant photo!", maybe that's not your style. There are lots of possibilities.

I think a more complete sentence would be "Congratulations, that is a great photo."