𝕏 is a Unicode character known as "mathematical double-struck capital X." The new logo is also nearly identical to the lowercase "x" in the Monotype font "Special Alphabet 4." ...

Twitter’s new logo is a Unicode character from a math alphabets subset. The previous logo was refined over more than a decade and heavily regulated online. The “Twitter X” dates back to 2001 ...

right there with you, bags-under-eyes emoji Unicode 16.0 release with new emoji brings character count to 154,998 New designs will roll out to phones, tablets, and PCs over the next few months.

If you come across a symbol you’ve never seen before, or you want to look up the unicode for a certain symbol, it may be a small challenge to search for it if you’re not entirely sure of its name.

People pointed out that it looks just like a decades-old Unicode character. "Unicode character U+1D54F (𝕏) was added to Unicode in 2001 and has been used in mathematical text books since the 70s.