Hi!
I recently attended a convention and had the opportunity to speak with the head of Canvas at Webtoon. She explained to me the process of which comics are chosen to get showcased on the main canvas page recommended titles section and on the app's front page where it has Staff Picks, Rising Star, Specials etc..
She told me that when a Canvas series does well enough (like has a pretty consistent posting schedule and a fair amount of engagement) that series will be put into a pool for either that week or month - however frequently they cycle those spots out.
And from that pool she and a team personally handpicks which Canvas comics get put into any of those spotlights. So there is technically an algorithm that determines what comics get into the pool, but then they are chosen by a person every cycle to be showcased in those slots.
Hope that helps!