Look at this graphic! Do you think the squares in the middle are taking more room than the other ones?
Maybe we are looking at a pyramid from the top, since the squares in the middle seem to be raised?
But it's just your naked eye betrading you, again. All big black and white squares are equal in size. Just the smaller squares placed in the bigger ones confuse our eyes/brain.
So, don't believe in every model you see for the first time. Always check a model thoroughly!
Cheers
Rune