Final answer:
Nick was amazed by the incredible variety and dazzling display of entertainment at the party, which included acrobats, lightning artists, and the kinetoscope showcasing a rich tapestry of performances.
Step-by-step explanation:
The thing that amazed Nick about the party was the incredible variety and dazzling display of entertainment. Whether it was the acrobats with beautifully parted hair and graceful gestures to the audience, the lightning artist drawing portraits with incredible swiftness, or the grandeur of the event as presented through the kinetoscope, which left guests like Trina in sheer amazement, Nick's experience was filled with wonder.
The mix of performances, including musical numbers, acrobatics, and new technological marvels, portrayed a rich tapestry of entertainment that captured the imagination and presented the party attendees with an unforgettable experience, exemplifying the sheer variety and sensory richness of the time period's social gatherings.
From the excited exclamations "What will they do next?" to the jocund company in the poem, the ambiance of gaiety, innovation, and artistic display dominated Nick's experience. This exciting array of activities and performances is what made the party such an astonishing spectacle for him and many others in attendance.