Whenever you smell those, always think: Worst Case Scenario!
Those fries you smell are actually undercooked, soggy and gross. They were under the heat lamp too long and are nasty.
The brownies were overcooked into a hockey puck, and require significant chewing. Eww.
The donuts weren't in the heat long enough, so they're doughy and completely nasty.
And all these things
WERE DROPPED ON THE FLOOR!