The AngelList team and a rotating group of analysts from the top VC firms in the world reviews startups after they are published and features interesting companies to investors. This usually happens no later than 72 hours after the startup profile is published. This review is very similar to one that would be conducted by a venture investor, considering product, team and traction.
If someone from the team doesn't contact you by then, you should assume that you won't be featured right now. Please keep updating your profile as you make progress.