Basically, it looked like an oversized wok, with a heating element in the bottom. You put the pizza on the tray, put the lid over it, and waited about 20-25 minutes. It never melted the cheese on frozen pizza that thoroughly, but it did the job.
Tried to find a picture of it, but failed.
EDIT: Curse you, Fred Smythe - I tried looking on eBay and couldn't find anything. Then again, I never go there otherwise.