Sylvia Else writes:

Presumably residue from the heat shield.

Aesthetics apart, does it matter if a less than pristine capsule is
launched when it's reused?

No, but I'm also sure that the outer covers (it's not the pressure
vessel you're seeing there) will not be reused anyway. And if they will
be reused they will get a fresh coat of paint. You surely don't want
even pieces of peeling-off paint floating around at the ISS.


Jochem

--
"A designer knows he has arrived at perfection not when there is no
longer anything to add, but when there is no longer anything to take away."
- Antoine de Saint-Exupery