Twitch uses a system of emotes which can be used in chat. Emotes such as Kappa or LUL can be typed or chosen from the global emotes list, with an image replacing the emote text when sent.
Many emotes used on Twitch display real people, and have varied meanings based on memes, in-jokes, or other references.
In June 2020 the TwitchCop emote displaying a police officer blowing a whistle - originally added in 2017 - was removed. This followed continued protests over police brutality in the United States as part of the #BlackLivesMatter movement.
List of global emotes on Twitch
Last updated: June 2020