Animations that look good in third person perspective almost always look heavily distorted in first person. Mirror's Edge is a good example because there is a third person perspective hack so you get to see Faith spider walking around with no head. Movement looks natural in first person but becomes the stuff of nightmares if you go third person.
In games like Fallout 4, they basically rig the mesh for third person and when you switch to first person, its just a camera with floating hands at "eye" level. They only render what the player sees, and since you only ever see hands and arms up to the elbow, theres nothing else there. Unless its a full on simulation, games tend not to render things the player can't see for efficient workflow and performance.
Mirror's Edge and Cyberpunk are different because the camera is mounted where the head should be and things like hair are not rendered to prevent clipping through the camera. You can look down and see your own body. Mirror's Edge is built for first person perspective only and Faith is rigged and animated for kinesthetics - the sense of you having your own body in the gameworld and experiencing motion. Cyberpunk is really similar to Mirror's Edge in this regard.
If you want real mirrors in Cyberpunk and to see V reflected in windows and puddles of water, CDPR will have to re-rig and re-animate everything. It can be done but there is a debate to be had over whether or not its worth the time and resources to do this.
Photo mode is something you can see in other games but it has limited functionality in Cyberpunk because of first person perspective. Warframe for example is a third person game with a photo mode called "captura". You can move around in real time and pause, rotate the camera and make cool looking screenshots. In Cyberpunk you can't move in photo mode. You can only choose from preset poses, presumably because V isn't rigged to animate naturally in third person.
It works both ways however. You can't play Warframe in first person perspective. Even if they did try to do it like Mirror's Edge, melee attack animations involve a lot of spins, twirls etc. Even if they re-rigged the model for this to look and feel natural in first person and built out a full set of bespoke first person animations, you would puke your guts out.
