It is rude to be disruptive when someone is performing.
Dave is a the comedy club where a comedian is performing and Dave finds a joke particulary funny.
Dave wants to signal to the comedian that he likes the joke.
"Dave remains seated but simply yells a quick ""Woo"" loud enough so that the comedian can hear."
Dave stands up and starts loudly describing, in detail, what he loved about the joke while the comedian is still performing.
The comedian appreciates Dave's vocal gesture of support and grows more confident on stage.
The comedian is angry that he's being talked over and interrupted and glares at Dave.