Why does Sidious/Palpatine keep his face hidden even when he meets Dooku meet on Coruscant?

Sid keeping the hood over his face is a trait of his personality. Its no more than "the way he is." Its a quirk. Its a habit. Same goes for the way he holds his hands gay-boy fashion when he walks.

Remember, Sid kept his face hidden from Vader when he first met him on the DSII. Its no different than Julia Roberts smile, or James Earl Jones' voice.

Its the way he likes it.




Which reminds me. Julia Roberts blows.

 

Maybe he just isn't taking any chance of someone on Corroscant seeing "Palpatine" with some very questionable/shady people, which may cause some suspicion to his other identity.

When he was on the balcony with Maul in TPM he had his cloak on also.