craigb
bapu
There are no "hidden" cows in that picture.
Some part of every cow is exposed.
To be hidden you should not be able to see any part of a cow.
HTH.
Ah, but that's the tricky part! Maybe there ARE hidden cows in that picture. I mean, how would you know? They're hidden, right? 
Has this got anything to do with the elephant in the room that folks never talk about?
I mean really, if there was an elephant in a room that I knew of, I'd be talking about it. What a story; there I was at home the other night and when I looked over my shoulder there was this elephant.
Cmon, tell me you wouldn't talk about an elephant in the room.
But what's this got to do with hidden cows? I don't know. Maybe they're hiding from the elephants. It begs the question, can the elephants we don't talk about , see the hidden cows in the room? Is that why the cows are hiding? But then if we can't see the cows how do we know they're there, let alone hiding. And of course is the room really big enough for cow(s) and an elephant.
Who could imagine life being so complicated.