LWIAY is an acronym of the PewDiePie's series of videos ( it stands for "Last week I asked you") in which he reviews his viewers's submitions via Reddit. It also may be a replacement for the second season of "Scare PewDiePie", which was canned because of PewDiePie's problems with WSJ.
What does Lwiay stand for?
LWIAY stands for (Last Week I Asked You)
Created by Pewdiepie, where youtuber Pewdiepie challenges his viewers to submit content, more specifically memes for his channel via Reddit. It is like YIAY(yesterday I asked you).
"Leave your entries in the subreddit bros and I'll watch submissions in the next episode of LWIAY"(this is the intro song for Pewdiepies's LWIAY videos).
A show running on Pewdiepie's YouTube channel where he reviews content submitted on the subreddit r/PewdiepieSubmissions.
It was inspired by jacksfilms' YIAY and started as a joke about Pewdiepie never uploading any original content (because it was an obvious copy of YIAY).