I believe they're evaluating the position in real time with the game review tool. When you're reviewing a game, if you disable the coach and go to analysis, playing a different move than what was played in the position will result in the machine loading for a minute, and then the move's evaluation icon will appear. I'm not sure how they apply that to a game that's going on in real time, though.
In any event, it's not possible to see icons while you're playing a game. That would be a little unfair if you think about it; if your opponent played a seemingly OK move and then "??" suddenly appeared on it, you'd immediately go from thinking the position is still equal to trying to find the blunder, when you should normally be using your brain to do that.
im wondering how do i get those brilliant/best/blunder kinds of icons when i make a move, the kind that they showed in the esports finals chess that happened. whenever one of the players makes a move, it will sometimes show the brilliant double "!!" or the "!". anyone know how to turn the setting on if there is a setting for it?