Often with big shows, there are separate elements that the production wants fans to be a part of. These are separately-ticketed events, since you can't be in two places at once, and because they often have different check-in times, locations, dress codes, age requirements, etc.
All shows and their elements are different, and they always vary. Please do not reach out to 1iota asking what each event sees, or how they are different.
If a show has multiple aspects, you are welcome to submit ticket requests for more than one, but if your request is approved, you will not be approved for others.
This FAQ has more information on Seat Fillers specifically.