Should I swap theatre seats with my friend for the second act?

At the interval, my friend held out her balcony ticket and said, 'Your turn upstairs. I want to see the actors' faces for a bit.' We hadn't discussed swapping.

We booked separately for the same play. I paid $72 for a seat near the front because I'd been saving to see this production. She chose a $28 balcony seat and said beforehand that she'd rather spend less. We planned to meet in the foyer and get supper afterward. I didn't think of the two tickets as a shared purchase.

I said I'd rather keep my seat. She went quiet, then said she would have shared a better view with me. An usher heard us and said to check with staff before moving. I returned to my original seat, but spent the next scene wondering whether I'd turned our evening together into an argument over $44.

We're seeing another play next month. How do I explain that buying different seats doesn't automatically mean taking turns in the better one, without making her feel judged for choosing the cheaper ticket?

The usher's response belongs to this scenario and is not a general venue policy.