"A toy-grade projector for a kid's room, and priced accordingly."
This product has a native 720p (1280x720) resolution. It can accept a 1080p video source, but the image you see on the wall will be downscaled to the lower 720p resolution, resulting in less detail.
This product is for someone buying a projector as a toy for a child's bedroom for occasional cartoon viewing. The extremely low price mitigates the risk, provided expectations are set to 'disposable electronic' rather than 'home theater'.
Anyone seeking even marginal performance for movie nights should look elsewhere. The unstated brightness is a serious concern, and the added cost of required adapters for phone mirroring pushes its effective price into a higher bracket with better options.