Had to look soijack up:

Soyboy Face, also known as the Soylent Grin, Nu-Male Face, Nu-Male Smile, Soyface and Cuckface, is an internet slang term referring to a facial expression associated with men described as nu-male or Soy Boys who are photographed expressing surprise or excitement with their mouth agape. Online, a variation of Wojak referred to as “Soyjak” is illustrated with the open-mouthed smile.