This sounds entirely right. Because I also have a recollection of that party room in the clouds. Actually, it's further refreshing my recollection---I think the main area was called "the Sprawl" or something like that? Maybe it WAS just a mirror, and the reason I haven't ever been able to find anyone else talk about it is that I was under a teenage misimpression about the name.

EDIT: AHA. Sensemedia apparently had a virtual community consisting of MANY themed MOOs, termed "The Sprawl," of which Snow was one; ChibaMOO was I guess the famous one, and was based on Neuromancer. This is more progress than I have made on this in years, so thanks!