Haier has created a smartwatch that it showed off at Mobile World Congress 2018 with a built-in projector that can actually project stuff onto the back of your hand. That said this isn't something which would have the capacity to be used for projecting media content onto a surface, such as movies or TV shows, but then again that doesn't seem to have been Haier's goal in the first place. As with any smartwatch the Asu as it's called is built to be an extension of your smartphone while also being able to do some of the same things. In this case, allow you to read texts and other various data related to apps or features on the phone.
In the case of certain functions like text messages, the watch is capable of projecting text messages onto your wrist, presumably so they can be read easier than on the smartwatch display itself. Judging by the images the visibility of the projected information may not be as easy to see as some might hope, but it does appear to enlarge the information a little bit. It's also worth noting that not all of the information being projected is the same information which is being shown on the watch display. For example, in the image below which shows the running app and timer open along with the time since the clock had been started, alongside two buttons, one for pausing the run and one for completing it, the projected content that shows on the top of the hand is not the same.
In the image above you can see the exact same graphic drawn on the display being projected onto the back of the hand, so it appears that some things will be projected exactly as they're displayed while others will be additional stats related to what's on the screen. The watch is capable of various activity tracking features like tracking steps, calories burned and more in addition to alerting you to notifications that have been received on the connected smartphone, and there's currently no exact release date or pricing information that's been confirmed, but it is reported to launch sometime in May and is said to be limited to the Chinese market.