describe-char missing info on unicode thumb up char

[Xah Lee]

there are these unicode symbols

ok hand sign 👌 #x1f44c
thumb up 👍 #x1f44d
thumb down 👎 #x1f44e

when calling describe-char on them, it doesn't give their names.

is this a bug? does it happen to just few chars, or perhaps all chars
outside basic multilingual plane? I know that many chars outside of
BMP doesn't have this problem.

 Xah ∑ http://xahlee.org/