Earlier quoted context omitted.
That has to be including all of Russia as part of "Eastern Europe" (indeed, if you drill down into the data, that's what's happening). When we're talking about geography, you can't include anything east of the Urals in the European subcontinent.
The Urals as a border is purely political and historical in nature. It has no particular geographic significance.
In Geology class they teach that the Urals formed about a quarter of a billion years ago when Europe and the Khazak land masses collided. I know this because we had to do a group paper on why such an old mountain range would be so unusually high. (Long story and not important.) Point is that though my degree wasn't in geology, and I'm only going from memory, I'm 99.999% certain that the Urals are the Urals for a critically meaningful geographic reason. At least, geologically speaking.
Of course, if this is all just political, then you can take any borders you wish to be Europe. I was only pointing out that if we're talking about landmasses in the geological sense, then the commenter was correct, Europe clearly does not extend past the Urals. Scientifically speaking.