The comic said:

The staff had the leftovers.

How !?

Stan-Miller said:

How !?

She might not have used all the chocolate...maybe

Stan-Miller said:

How !?

Probably a joke about those idol cooking shows that sell the idol's popularity despite the food tasted bad.
Staffs have to shared the food among them because the guests are not going to eat it :D

Stan-Miller said:

How !?

Because the staff always has to eat the leftovers. It's basically law in Japan. The elderly people who run the country complained about "wasting food" on cooking shows by pulling out pre-cooked things to save time after putting something in the oven, so now, they assure everyone that the staff eats everything, and no food is wasted, no matter what.

In Sayonara Zetsubo Sensei, they had a scene where Kaede was in a cooking show literally throwing the food over her shoulder on the floor or into the garbage and the "staff was forced to eat it deliciously later" tag popped up, as well.

NWSiaCB said:

Stuff

The "trash can" must have also been one of the staff.

Stan-Miller said:

The "trash can" must have also been one of the staff.

Well, there's two ways to interpret it.

One is that they're just making fun of how clearly easy it would be for those sorts of things to just be lying. (In which case, you'd be right.)

This being Sayonara Zetsubo Sensei, however, it's just as likely that the sadistic characters were implying that they were purposefully throwing food on the floor just to be able to force the staff to lick it up afterwards... and she was continuing to stomp around on the food after throwing it on the floor, and threw extra things on the floor, including not particularly edible things, for no good reason.

Akashi: MY model!

Stan-Miller said:

How !?

Hint: Iku.