Sorry, I just saw this question!
I think we are using the term in a way that’s non-standard in the IF scene. We technically accept “sequential art” (i.e. comics) that are interactive for the magazine (nobody has ever submitted one), and I think we mean “panel” to be one section of the story–more or less a page.
Honestly it is kind of a confusing way of doing things and I think going forward we’ll probably talk about some other way to count that kind of thing.
For the purposes of this jam, I wouldn’t worry about “panels” unless your submission is primarily graphical in nature, like a comic with illustrations and words. In that case, each illustration that makes up a “page” of the game would count as a panel.
If anyone is working on a visual novel type format–like something in Ren’Py, for instance, I guess each background scene would count as a panel? But again, re-use of a background scene is fine.
Again, we’re not really interested in policing for edge cases, but just want to nudge people in the direction of minimalism for this jam rather than developing elaborate, lengthy games.
Last year we did get one submission that was interactive sequential art, if you want to get a sense for how someone else interpreted that restriction: https://odris-den.itch.io/fill-the-void