I really enjoyed those. I've worked with and socialized with lots of Russians over the years and I don't know what it is exactly, but something about the little details of the clothes, the haircuts, the furniture etc. all work together in a way that makes it easier to identify someone as Russian rather than another light skinned nationality.

That said, Ukrainians and Russians don't like to be confused with each other so as I learned the hard way, it's often better to just ask, if one is curious.