entonces el significado de ese ''kappa'' seria como un trollface?
Según Urban Dictionary:
The main symbol/emote of Twitch.tv.
It represents sarcasm, irony, puns, jokes, and trolls alike.
If you see this term used outside of Twitch.tv, then this is not the correct definition.
Usually used at the end of an ironic or sarcastic sentence. Sentences that contain a Kappa should not be taken seriously.
If you search "Kappa Twitch.tv" in Google you can see what the emote looks like, and why it is used as it is.
Pero yo nunca lo usé ni lo vi en los foros por donde paso, así que ni idea de en que contextos se usa.