Apple’s claim of it being 5mm thin is a bit misleading - the back bulges out from the razor-thin edges almost like an old CRT television, and in the center it’s about four times as thick.
But it’s smaller, lighter, and thinner than ever. It’s still very much an iMac, with a big black bezel surrounding a big screen, an aluminum chin below with a glossy Apple logo in its center, and a tilting aluminum stand sticking out of the back. This year's iMac appears to have undergone the computer version of elective cosmetic surgery – it doesn’t look different, just better.