This is the only appearance of Lyndsey Ballard. Her backstory is not an allusion to any previous installment.
The stardate given for Ballard's death, 51563, places it between the fourth season episodes of "Hunters" and "Prey."
This episode was nominated for an Emmy Award for Outstanding Makeup for a Series.
Lyndsay has a habit of being late. In her nightmare after leaving the captain's quarters, she comes into the mess hall late, and the first thing said to her is "you're late." It turns out that it's her funeral. This is presumably a reference to the American expression, "late to one's own funeral" for people who are habitually tardy.
The Kobali language is the only alien language original to Star Trek: Voyager to be heard extensively.