A fish it is, with shiny scales and head and tail and all! How... exactly are they supposed to eat that? As the cart moves closer, John can see it in more detail, but all he can see is well, a dead fish. It's not until the platter starts to float towards the table that John notices the slit down the middle and starts to get an idea (does it... is it inside like an envelope?), though he's now also confused by the pot full of red substance (is that berries?) floating close behind. When it lands softly without a sound some of his confusion is answered: the fish unfolds in front of them like a book, revealing the pale white fish flesh inside. (Minus the head and tail, that is. Those don't unfold. They don't seem to be a part of the meal, thank goodness.) And immediately afterwards, the rest of his confusion is cleared up, as a spoon dips into the jar and begins drizzling a thin line of the red substance (is that... jam? On fish? Well, he was right about the berries at least) over one side of the fish and then the other, each getting their own small berried stripe.
The jam jar is returned to the cart and from underneath the house produces a bottle of... wine? (He's not going to drink that, is he? No, he shouldn't, especially with what's going on tonight, and also alcohol is bad, and he's too young and not allowed it... but he has no idea how to decline.) While the house is pouring the clear white substance into the tapered glass, he peers over at the fish instead. (He can bring up the wine later? Maybe? Or see what Rosy does?)
The flesh is gently steaming, and in addition to the jam substance there's a thin layer of some sort of thin clear sauce speckled with bits of green on either side, leaking down onto the platter now that it has more room to escape. "So, do we just take half a fish each?" John asks as the house finishes pouring them wine, leaving them the bottle on the table.