Some odd behavior in front of mirrors ...

I've noticed something for years about my wife and daughter when they are looking in mirrors, trying to gauge whether they like the clothes they have just put on: They tilt their heads, either to the right or left.
Now, they do NOT do this when they are looking only at their faces ... only when they're examining the whole human package.
I recently caught myself doing it as well ... in one of those "is my gut getting bigger" moments, standing there in my underwear.
And then I started...