In online blitz chess, players take turns controlling their pieces which move in different ways (mechanic). Pieces can capture an opponent’s pieces (each has a value) (mechanic); if the capture of the opponent’s King piece is inevitable on the next turn, the player wins the game (mechanic). Players only have a limited amount of time to spend across their turns for the entire game (mechanic). If your timer rules out, you [generally] lose (mechanic). Online blitz chess also introduces premoves: locking in your next move before the opponent makes theirs (mechanic).
One common dynamic is lots of capturing and recapturing. This utilizes the mechanics of piece movement, capture, and premoving. I find this dynamic relaxing, as you can make many moves in almost autopilot and then just zone out as a set of captures automatically plays out via premove. When I play chess to relax and zone out, this premove capture–recapture dynamic leads me to view abnegation as an aesthetic of online blitz chess in particular.
Another common dynamic is the time scramble. Due to the timer mechanic, oftentimes players will both be low on time during the end of the game. At this point, it’s just an exciting scramble to see who can move faster to run out the other player’s timer (dynamic). I find this a fun form of competition (aesthetic)
A third common dynamic in online blitz chess is choosing their opening moves and playstyles based on their personalities, choices, and what’s possible given the mechanics of the game such as piece movements. Most basically, playstyles can be divided into attacking versus defending. The ability to choose your playstyle and see what opponents choose means that, for me, online blitz chess can be a fun form of expression (aesthetic).