"A toy projector with modern connectivity but a picture that demands total darkness."
The 'Support 1080p & 4K' claim means the projector can accept a high-resolution signal, but it then downscales it to its own, much lower native resolution. The image you see will not be 1080p or 4K, it will be significantly softer and less detailed.
This is a potential buy for a child's bedroom or for someone who wants a disposable 'screen' for a camping trip. Its low price makes it a low-risk novelty, but it should not be considered for any serious viewing.
Anyone seeking a projector for movie nights or use in a room with any ambient light should save their money. A used 1080p projector from a reputable brand will offer a vastly superior experience for a modest increase in price.