OK - so I found the existing thread (my apologies for starting a new one 🙁 )
Anyway, I thought maybe the thing in the bottom left of the pic is the top of an R2 unit? If you imagine it lying on a platform in front of Mace it should sort of make sense.
Is Mace lammenting the 'death' of a droid? Is this how the film will finish? Maybe Anakin sends a message to the jedi from his imrisonment with Sidi, and Mace has just watched a holo message that is basically saying "It's no good, I'm totally off to the dark side, all the best with the war an' all".
That would be a cool way to end EpII, with the JC recieving a message from Anakin saying "Forget me, I'm totalled" - but then, isn't Mace supposed to buy it himself in EpII, so presumably he won't be around at the end?
Maybe he's just recorded a message himself and is having some quiet "Jeez, sure hope this gets through" time before closing R2s head and loading him into an escape pod?
I'm off on one - but it's a cool pic. V.exciting 🙂