Lul

Meaning
LUL  is a Twitch emote featuring a picture of video game reviewer John Bain, better known by his online handle TotalBiscuit. The emote is typically used to indicate laughter in a similar vein to typing abbreviation of LOL

Origin
The guy depicted in this emote is the video game reviewer John "TotalBiscuit" Bain, and this is taken from a photograph laughing in an unknown Gaming event. John is known for his passion for WOW and SCII. In 2013 Total biscuit used this emote in his stream, back then it was known as "CynicalLaugh", but then a photographer who took the original image requested to take it down. Eventually it was taken down, but it was also added to BBTV chrome extension which made it popular, and the command "LUL" After a while it was added to the global twitch chat emotes, and anyone could use it with or without BBTV.