Mace Windu is using an earlier version of his lightsaber hilt, lacking the distinct gold embellishments. The blade remains its trademark purple, however. Notably, he is not using the generic hilt that he was briefly seen carrying in Star Wars: Episode I - The Phantom Menace (1999).
Count Dooku and Mace Windu are presented here as contemporaries, with Windu perhaps being the elder (certainly the more authoritative) Jedi. Christopher Lee, who originated the role of Dooku in live-action, was more than 26 years the elder of Samuel L. Jackson, who originated the role of Windu.