Is that a marmalade box?

There's a renaissance still-life of a table with a bunch of banqueting stuff, and what looks like an open marmalade box in the bottom right corner.
Go here, http://www.wga.hu/frames-e.html?/html/f/flegel/index.html and scroll all the way down to Still-life with Parrot (George Flegel b1566-d1638), and there's a round-ish box that looks like it's filled with jelly.
Hmm, those red boxes behind the parrot might be trencher boxes.