From what I've seen, sometimes the computer correctly assesses that the "bad" move opens up some kind of "checkmate in 45 moves" that could technically happen, but requires the opponent to see it 45 moves ahead of time and play something that would otherwise appear to be completely sub-optimal until something like 35 moves in, at which point normal peak grandmasters would finally go "oh okay now I get the point of all of that confusing behavior, and I can now see that I'm going to get mated in 10 moves".
So, the computer is "right" - that move is worse if you're playing a supercomputer. But it's "wrong" because that same move is better as long as you're playing a human, who will never be able to see an absurd thread-the-needle forced play 45-75 moves ahead.
That said, this probably isn't what GP was referring to, as it wouldn't lead to an assignment of a "brilliant" move simply for failing to see the impossible-to-actually-play line.
Poker is funny because you have humans emulating human-beating machines, but that’s hard enough to do that you have players who don’t do this win as well.
But mostly what happens is that a move isn't so good, but it isn't so bad either, and as the computer will tell you it is sub-optimal, a human won't be able to refute it in finite time and his practical (as opposed to theoretical) chances are reduced. One great recent example of that is Pentala Harikrishna's recent queen sacrifice in the world cup, amazing conception of a move that the computer say is borderline incorrect, but leads to such complications and a very uncomfortable position for his opponent that it was practically a great choice.