Most likely the customer or some random person adjusted the valves, which shouldn’t affect anything actually. A job like this wouldn’t be signed off on, even a bad plumber wouldn’t do this… fucking lol.

But it looks like the flow cartridge or aeroater is missing and that’s all. Most fixtures are controlled by flow regulators so messing with valves doesn’t fuck with them. That’s how tradesmen know this isn’t just a bad plumber fyi.