Admiral Buenamigo is wearing the black/gray style of uniform seen in the TNG movies and latter seasons of DS9. An admiral's uniform of this style should have rank pips on both sides of the collar, yet he only has them on his right side.
When Mariner arrives at the "salon" in her uniform, the other attendees mock her uniform, saying the dress code is always "Betazoid casual." Betazeds are known for their culture's nudity. "Betazoid casual" would not be the sweats and athletic wear the party-goers are seen wearing.
Jennifer states that she and Mariner being the only ones at the party not stunned is "kind of a bad look," implying that whoever discovers the stunned crewmen will blame the two of them for stunning their fellow officers. Mariner then stuns the two of them to rectify this. But there were at least 6 eyewitnesses to Mariner stunning the other party-goers.