the info's from 18 July set diary in Hyperspace on the official site. Take a look there for the full scoop or I have included the important passages below.
a scene shot today was originally set in Palpatine's Office. A quick rewrite kept the scene intact, but changed the venue. What was originally a private meeting has moved into a very public space.
After a morning of shooting in Palpatine's Office, the camera crew moves to a very sparse set on another stage. It's what people generally imagine a digital backlot set to be -- blue curtains and blue stage pieces everywhere. The date in the latest script has this revision occurring on July 14 -- a scant four days ago. On a nearby table, I see a pile of five printouts showing Ryan Church's concept art of this new location. They're all dated July 13. In these past four days, Gavin Bocquet's Art Department has whipped up a blue representation of the new set's contours, complete with fully detailed chairs featuring miniature monitors and control keys in the armrests.
In postproduction, this minimalist blue environment will become a Coruscant theater, with tiers of viewing boxes and an elaborate stage production yet to be determined.