Sometimes it's a hologram, which would be cool even if the fidelity were a bit shit, but it's interesting that art directors make them pretty bad looking even in fiction, presumably as a cue to the viewer that it's a hologram. Any fiction that portrays holograms as opaque and convincing usually plays it for surprise, because standard-issue holograms in fiction aren't convincing.
In previous shows the Federation has demonstrated the ability to create totally flawless and interactable holograms.
Yet somehow in this show everyone has switched over to glowly flickering interfaces hovering over your desk.
In the headquarters of Star Fleet, a giant hologram of a star ship is in the atrium, and it glitches out for a moment as the camera looks at it just to let the viewer know it's a hologram.
Not only is there no reason for holograms to glitch out all the time assuming that the technology could be created, but this TV series has already demonstrated their ability to do this much better!
The hologram that follows the main characters seems to be pretty high tech, and looks flawless. And they show the hologram stuff by having her move through objects.
But when the main characters walks around the city, you see hologram commercials that are the size of buildings. Those don't look lifelike. They're transparent and have limited colors.
Or many others did too. Earth Final Conflict for one, the hand tablets. Hell Tech works amazing in black mirror, one might argue WAY TOO WELL.
As for Star Trek holograms, when the episode doesn't want to "play for surprise", it usually briefly shows the hologram appearing - which uses its very specific VFX, so that it's immediately recognized as a hologram (and not confused with teleportation, which uses a different style of VFX).
From the Linus Tech Tips hands on review of one (Dec 2018), they seem like they're already useful for some scenarios. eg shop windows:
From the video you linked the opacity seems to be much better than I expected. I'm hoping one or more of the high end TV shops put this into their show room so I can see it in person.
https://www.theguardian.com/world/2020/aug/18/loo-with-a-vie...
The black LED pixels can supplement the dark/opaque colors, while simultaneously supporting transparent colors with OLED pixels (i.e. like the png format).
I always figured this was for cinematographic reasons. It lets you see what’s on the screen and the character’s face simultaneously.
Transparent OLEDs are not that new, they have been around for a while. See this Thermostat by Johnson COntrols.
https://www.amazon.ca/Thermostat-Johnson-Controls-Translucen...
http://media.comicbook.com/uploads1/2015/01/tony-stark-trans...
This technology is being use by Xaomi to make a "transparent TV"[1] which in theory you will be able to buy. (I realize that not all of these sorts of announcements survive until actual product shipment).
It will be interesting to see one of these "in the flesh" as it were, I'm at a loss what you'd have behind it that wouldn't make it really really annoying to watch, but the cool factor could be right up there.
[1] https://www.theverge.com/2020/8/11/21363861/xiaomi-oled-tv-t...