Are those Happy Socks, Vicious? I have a few pair that look just like those. I noticed the heel showing on mine too the other day, but that particular pair were brand new, and I expect them to shrink a bit. I wear an 11.5 in most shoes, so the socks are not oversized for me.
Is it really a style no-no to have that heel square showing? I never knew that. Seems like a little peeking out wouldn't be so bad; kinda nice to show a little of the color accent, actually. No? Or no.