First had a call with an internal recruiter, then I was sent a paid take home task. I was given the freedom to do it whenever, but to not spend more than 8-10 hours. In the task you can choose out of two briefs/ideas, that you're suppose to research, and flash out production ready, highest fidelity output, including prototypes, motion, brand. They also judge the presentation itself. It needs to look good.
Then the task would be reviewed by the team. If passed successfully, than there's a portfolio review. Not sure if there's another step after.
I love MetaLab, they're one of the best out there, but I think the task asks for too much. To do it properly means spending more than one day. If you're testing visuals, then don't ask for product thinking. If you're testing for product thinking don't ask for prototyping/motion. Maybe split the tasks in a couple smaller ones. Also I think it's less fair to do a task before portfolio review, as it makes the candidate put a lot of effort towards the job before the company made any effort. At least it's paid.