How did Mandy/woman at party recognize Cruise character?

Rating: Null/10 (13 January 2004)

Kubrick is known for his attention to detail, so I'm left wondering if there were any clues as to how the woman at the masquerade party/orgy recognized the disguised Cruise character? There seemed too little time for his arrival to have been "announced" to the party... Later, we find that this woman was likely Mandy, the OD'ing woman at Ziegler's earlier party.

Of course, resorting to calling it all a dream can eliminate any incongruities, but that seems too convenient.
And, if then it was "just a dream," are we to extrapolate some sort of huge connected thread (and meaning) between the Domino hooker, the surreal Russian costume renter (with the nubile daughter), and the debauched aristorcrats' party?