Review the sentence:
Too hungry to wait for Brenda's return from the restroom, the bowl of
egg drop soup quickly disappeared.
Too hungry to wait for Brenda's return from the restroom, a phrase, has no target in the sentence to describe. When a modifier has no word to describe, it is dangling.
To fix the problem, you could revise the sentence like this: Too hungry to wait for Brenda's return from the restroom, Leonard quickly ate the bowl of egg drop soup. Adding Leonard to the sentence lets the reader know who has no table manners!