As you can see in the image below (click to enlarge), the board says "STEAMBOAT", which lead some analysts to speculate that one of eMagin's VR customers is game developer Valve Corporation (as they publish the STEAM gaming platform).
Valve has been confirmed to work on a next-generation VR headset. eMagin's CEO declined to comment on the Valve suggestion, but did say that this display was indeed developed for a partner, and that the company has a second, larger, company it is collaborating with. eMagin announced a Tier-1 consumer electronics company partner back in 2017, and a second AR partner in 2020.
There has been speculation that Meta (Facebook) is one of eMagin's partners, and some rumors also point to Apple.
Disclosure: the author of this post holds some shares in eMagin