Not much.
LH pocket has 12volt power supply which as yet has to be located to a more suitable place.
GPS Charger when in use.
Phone and charger during charge at campsite. (other wise in top case)
Can also slip sunnies in there on the move when it gets to dark to wear them.
Bag of barley sugar lollies or similar on longer trips. (sometimes).
Small flat metal plate for side stand for those not to firm parking spots. (just in case)
RH lockable.
Store GPS when I leave bike in carparks etc.
Sometimes wallet. (usually in top case)
OzStoc cards (now that I have them.)
Tool kit supposed to be stored here but it's under the seat.
My helmet came with a clip on nose guard for protection from the sun so that's in there as well.
My phone is loaded with music should I want any.
That should satisfy those somewhat more curious souls amongst us.

Alan