Often in live online work there are multiple stages to be taken into consideration:
The stage of the whole piece
This is the entirety of what's seen, the combination of all the performers' stages and any additional material. This is the level at which videoconference presentation decisions are made, such as using the grid or working with Spotlight mode; and the level at which layout decisions are taken in OBS.
The stage of groups of performers
This is the way in which groups of performers combine onscreen, where patterns may form based on similarities of visible content, colour consistency, scale of performer/distance from the camera, etc.
Jennifer Walshe: zusammen iii (Bastard Assignments Lockdown Jams 2020): https://youtu.be/judOvlKtanE In this piece, Josh - in the top right corner - is differentiated from the other three performers through differing action, sound related to that action (the other performers are all silent), and makeup. The other three form a cluster - a chorus, if you will - based on the similarities of their actions (all switching between face yoga and silent speaking to camera), and contrast from the soloist.
The stage of the individual performer's frame
What can be seen of the performer and their surroundings in frame, including their position in the frame, scale and level of detail (arising from how far they are from the camera). This is tightly aligned with the performer's physical environment.
The stage of the individual performer's physical environment
The significance of this 'stage' is in how it is arranged, used, and how it relates to the individual performer's frame. This stage may be abstract and hard to define physically, but it becomes wider the further back from the camera you move.