For a problem with a specific listing — a scam, fake photos, counterfeit goods, or a safety issue — open the listing and tap the flag icon to report it.
A report puts the listing at the top of our team's queue to look at, usually the same day. It doesn't hide the listing on its own: a single report from an anonymous account can't take a real seller's item off the marketplace, because that would be too easy to abuse. If we agree with you, it comes down.