It’s nice to see Valve have given this a fair bit of thought. There’s a spectator-only HUD with information like health and ammo counts, to give you a better idea of the player’s situation. Valve mention people often check their health by glancing down at their glove, rather than holding it up to where people watching on a monitor will be able to see.
Streamers can also enable spectator camera smoothing, which will “smooth out or remove the rotational jitter that comes from playing a game in VR”. Again, this only impacts spectators, and apparently has “minimal to no impact on graphical performance”. Players can also change which eye the spectator view displays output from, and Valve recommend setting it to the eye you aim down “so people watching you play will be able to look down weapon sights with you”.
The post also explains how to change settings so that you can capture smooth and cinematic video, but do warn this will result in disorientating lag. If you want to make a short fancy video, though, Valve have got you covered.
Details on how to twiddle with all of the above can be found here.
Half-Life: Alyx is out later today on Steam for £45/$60/€50. It’s also bundled for free with the Valve Index and the Vive Cosmos Elite, which you can buy for many hundreds of pounds from Steam and Vive’s website.