The emote SMOrc is part of the original Twitch.tv emotes collection.
SMOrc refers to the Space Marine Orc face from the Warhammer 40k series.
The emote can be used on Twitch.tv to react to a Hearthstone player picking the Hunter character and “going face” (attacking only the other player and ignoring its minions).
SMOrc or the Space Marine Ork character is originally from the Warhammer 40k universe. They are known for their aggression, thus the meaning of the emote on Twitch.tv.
They are savage and crude yet the most successful species in the Warhammer franchise, because they are outnumbering every other species, however they are split in tiny empires and often fight each other.
They are a comic relief in the Warhammer 40k universe thanks to their appearances, humorous behaviour and language as well as the ramshackle technology with funny names, but it won’t stop them from being a threat to other species in the universe.
Twitch.tv got its own version of the emote as part of the original collection, however its original upload date is unkown.
As of 10/12/2019 according to the website StreamElements, SMOrc is the 7th on the list of most popular/used emotes on the website Twitch.tv, making it one of the most popular emotes