Group: Punctuation
U+0040
0040
64
@
\40
\u0040
\u0040
40
The same character is drawn differently by each operating system and font.
Unicode standardises the meaning of a character, not its drawing. Apple, Google, Microsoft and Samsung each ship their own artwork, so the same code point changes shape between devices.
The character is copied as plain text, so it pastes into any app that accepts text. If the receiving app has no font for it, you will see an empty box instead.