So is the idea that the newborn has some visual stimulation when laying in crib.
I know that a number of pico projectors have smartphone apps (though I do not know how much I would trust these applications). Many projectors also run a version of android and you can download apps. Years ago I used a free android app that would pull pictures from a nextcloud web share folder. I think I had it installed on an older kindle. Setting this up on a windows PC was even easier. Use nextcloud's desktop app to sync a folder of images and then setting that folder as the source for a slide show or screen saver. I can upload pictures to the nextcloud manually or automatically from my smartphone or my pc. I believe there might also be a nextcloud slide show freature that works through the web browser.
While projecting onto the ceiling certainly is a little more magical, I might consider just mounting a display or android/pc tablet on the ceiling our using a mounting arm that move the display in the directions you would like. When looking at pico projectors I would consider the noise level. Their fans can be loud. I would also make sure that it can charge the internal battery, while in use. I do not know how long their bulbs last. That used to be an issue with projectors. If you are also interested in playing sound, you will need to work out the audio. Also, I do not think most projectors are designed to be on and running for 8 hour stretches. And finally, most inexpensive projectors are going to get bleached out with any light on.
If I were trying to build a system, I might just hook up a pc to the projector/or display and have the screen saver pull from a local folder I could add images to over the network.
Similarly, I might look at one of the Raspberry Pi projects for "Digital Signage" There are some really powerful systems out there. https://digitalsigna...signage-open-source/
There are also digital picture frames that allow you to load images onto the "picture frame". Some allow you to load images remotely. In my opinion they are expensive, but they can provide a way to "beam" images into family member's homes in way that is easy for persons not familiar with computers and that is aesthetically pleasing. When I looked into it years ago, there were quite a few options you build your own with a cheap tablet.