"You're (really) something!" in Polish is "Ty to jesteś!"*, meaning literally "You are the one that is!".
This seems more logical than the English expression - your existence is more, your [way of] being is the right one.
Yet there is, hidden within this phrase, a sense of hierarchy that verges on arrogance - a value judgment on being. I prefer the English version - it sounds more modest, the paradox (you-thing) gives it the feel of a good fetish - you are [my] fetish.
We can also see it as edifying: I can see you objectively and that sight is grand.
You are something else: you are fundamentally unattainable.
All the photos are by Asger Carlsen, from the series Wrong, 0 and Detour.**
* The Polish expression, however, has a rather pejorative connation, while the English one usually means we are impressed with the other person. Still, both have the basic meaning of awe and amazement, and both can in some circumstances be positive or negative.
** The first two pictures are not, as someone suggested, photos of real handicapped people. See the entire Wrong series for more.