The idea is that they complete tasks ahead of schedule and then slow play results to the predetermined deadlines. It's hilarious to me that people are saying this is a genZ thing, since this shit has been going on in tech fields forever. Literally everyone I have ever known has taken "working vacations" by pretending some work is taking longer than it really is.
Bonus points if you are smart enough to still turn it in a day early to keep the heat low.