So, heads I get. You know, there's a head on it. So when you look at it, you're like "yo! that's a HEAD!"
But tails?? You're all like, "um...that's a building" or like "um, that's a bird." There's a noticeable absence of any TAILS.
The tales strangeness
I prefer the much more refined Obverse and Reverse when describing a coin. Heads or Tails is so Farm'y'.