I think eggs are pretty conservative and a safe bet in the imagery of ceratopsian omnivory. I imagine the Protoceratops going back and having a go at the Oviraptor too, though.
I like ceratopsians in general (thanks Peter Dodson), but there's something about Protoceratops, especially if you imagine it as a spunky little ball of aggro and Napoleon complex. I've got a lot more Protoceratops sketches and drawings in me, some of them eating stuff they shouldn't be eating. Or should they?