iPhone may have been compromised

While we were viewing properties, my real estate agent needed to contact her kids school and her phone wasn't working (she said). I let her use my 14Pro to make the call. I opened the phone and dialed the number for her. I walked away a short distance for about two to four minutes. Never heard her say anything but she said the call was done. When she handed it back, her screen photo was on my phone. While she had both phones, they were stacked one on top of the other when she turned to hand them to me. I've never had someone else's picture show up on my phone when they were to each other. There was not other phone call in the log nor test messages sent or received in the log. Was that enough time to download malware? Could she have been trying to get money from ApplePay? I don't know enough about applepay to know. I've never paid for anything by tapping my phone but I've seen others do it.

[Re-Titled by Moderator]