crown, diamond at the end of players name


It indicates that the player has proven himself to be an aspirant jedi and is starting to master lightsaber skills. You can take a video of yourself kicking Darth Vader's bottom and send it to the administrators of chess.com, they would reward you with a colorful diamond next to your name.

If you're a premium member you can choose which icon to display. If I remember right, the red diamond is one of the options only available to diamond members.

What about this GG?
Flair.
https://support.chess.com/article/673-how-do-i-change-my-icon-or-flair