From #15930 (comment) conversation.

@jaaydenh: Would be nice if we started using 2 letters for the fallback case. For example, the first letter of the first 2 words in display name. For example, if you look at the users page on dev.coder.com there are many duplicated avatars for the letters A and B that it doesn't serve much purpose as a identifier.

@BrunoQuaresma: Since we don’t control the name or display name, we can’t enforce them to have at least two words to display two letters. In such cases, we would display only one letter, correct?