More generally, this remarkable aspect of go: The fact that through this discrete, deterministic game, even online with no opponent to see or hear, you can sense emotions: fear, confusion, shock, surprise, cockiness, desperation.
It's remarkable. I began to notice this even at lower levels (like 18k), meaning it only takes a mild competence at the game to be able to detect opponent's state of mind.
This is similar to, but different, than individualistic play style, but that is a future post.
Fear: it's most often seen in handicap games, and in many ways a fearful type of play is the same as a conservative type of play, which is actually wholly appropriate when receiving a handicap (or being in the lead, in general). It's shown through things like falling back from fights, extra plays in your own territory just in case, things like that.
Intimidation: The opposite of the fear coin, it's usually the higher skilled player exercising this. Seen in wild plays, overplays, cutting everywhere, things like this. When your opponent is fearful of your skills, you can throw stones into their territory and be virtually guaranteed a response (making it free, essentially). If opponent is especially scared you can even get multiple responses to one play.
Shock and Surprise: This is one of my favorites. You can see this often when you capture or kill a group, usually by a sudden pause in play pace. This is different than a pause due to a tricky situation developing, often when a big group suddenly disappears, presumably due to a blunder. This surprise extends into shock when the next couple of plays by the surprised opponent are done poorly and without appropriate thought -- often playing a stone into atari (w/o other benefit) or similar silliness. I've been on both sides of this situation a lot. Man, that pause...
Cockiness, Desperation: Oddly, these two both look like intimidation: wild plays that do not look like they have a chance of success. The difference is context: if the player is losing it looks like desperation, if winning it looks like cockiness. If the player is of higher skill and/or giving a handicap, it can be considered intimidation.