It might have been Laura depending upon the timeline. She was pulled out of the Black Lodge so it's possible that she was sent there. If time exists in the same way in our world and the Black Lodge, then it was something else that we will encounter later since Cooper was released at the end of the episode yet it was at the beginning of the final interaction between the lovers. 

If it was the evolved arm, then it would have been its doppleganger or a hybrid between it and Laura, perhaps. Or possibly another female caught in the Black Lodge. 

In Secret History there was a thing that sounded like a classic "alien," but which the archivist seemed to think was not necessarily an other-worldly thing but rather a this-worldly manifestation of evil... that part of Secret History dealt with the FBI's involvement in extraterrestrial research (along the lines of what Major Briggs was up to). SO, might the manifestation in the box be something similar to what appeared as an "alien"? But in other terms might be called a "spirit"? (Like those said to inhabit the Black and White Lodges?)

I agree, r0byntn. I saw and thought the same.

I too thought it was a being from Project BB. 

I loved this scene! And yes i think it's something like an alien-ish thing or a spirit from the BL

Judy? Laura? Josie? Jeffries?  Whatever it was, it was beautiful and made me squee with glee. Mr. Lynch is back to guide us through this hellish mortal coil in grand style.   All that is required is patience and an open mind.  

At first I thought it was the Venus statue from The Red Room; it seemed to share the pose and have a feminine form. But then it morphed into that alien-like being. So maybe it's both? Or neither? 

I seem to definitely remember that a character from the original series (or the movie) had a dream about a "glass box." (in a tall building?) I thought I'd dreamt it at first, until I told my friend who also seemed to remember something like that. Anyone else? 

The thing is, I've been trying to google this for the past half hour and I can't find anything, it's driving me crazy, I don't know if it's real or if I'm making it up. Maybe it's from another David Lynch movie

It seemed like Laura to me - it mirrored the last scene when she elevated out of the black lodge shreiiiiking like a demon!!!

if I remember it started low on the right side, stood erect walked to the left (as when she was whispering to coop) then BLAMMO!!!   Like the spectators were experiencing a shadow box view of the final black lodge scene

the timing linked with coops weird pre-murder entry to the box

just speculating though need to rewatch 

Posted by: Kara Lefevers

 

It might have been Laura depending upon the timeline. She was pulled out of the Black Lodge so it's possible that she was sent there. If time exists in the same way in our world and the Black Lodge, then it was something else that we will encounter later since Cooper was released at the end of the episode yet it was at the beginning of the final interaction between the lovers. 

   

Yes this! 

If you squint really hard, you can tell it's Donna.

Given that the FBI doesn't know who the building and the glass box belong to. Who else then is interested in a Black Lodge portal?