[willyd]

I don’t know what that poster was talking about... companies routinely use mash potatoes instead of ice cream during a shoot. Soups have steaming cotton balls placed behind them and glycerin is used to make burgers and steaks look juicy.

[Albion Wilde]

Soups have steaming cotton balls placed behind them and glycerin is used to make burgers and steaks look juicy.

Yep. Back in the day we used to put a lighted cigarette in the saucer behind a cup of coffee to let the smoke look like steam.