Parallax, sunlight intensity, directionality, heat. It's a pity we don't have affordable (or even any?) artificial windows that even emulate the sun. Just think how much more economically buildings could be made if they had effective fake windows.
You know, I co-founded a smart LED lighting company well over a decade ago and we considered this market.
It seems like the potential applications might make this viable now. Cruise ships are a tiny market when compared to all the dead commercial office space in downtown cores that people wish to convert to residential but can’t because of lack of sunlight and similar reasons.
There are some other implemenations listed on this page. The trick is to make sure the light rays are parallel as if coming from an infinite distance like the sun. To create the blue sky effect the easiest way is to pass the light through soapy water like in this video posted above https://youtu.be/6bqBsHSwPgw?si=fWO5-pYa6kPYKLZO
You can also buy this from Alibaba - just the real thing, not the LCD flat panels. (the real ones are 10-20cm deep). I got a few two winters ago, and they are amazing for dark and gloomy Polish winters.
That's awesome, but the most powerful one is 9000 lumens from a 1200x600 mm panel, which is 10000 lumen/m^2. I don't think that's good enough for a proper sun effect since sunlight is 100000 lumens/m^2 and even outdoors in the shade is brighter than these devices. But it's certainly a step in the right direction and no doubt much better than natural light for you.
The TV would give you the ability to change the view. Have a couple of different 24 hour video loops so that it shows sunrise/sunset, clouds, storms (only if you had a good subwoofer to rumble with thunder) and then sync it to your clock.
However, I would be really impressed with a lenticular screen so that you get the 6-DoF type of view that would change the paralax view as you moved around the room a bit.