This may not be pressure to you but it feels like it and is very annoying. There's nothing wrong with interacting with someone and closing out the conversation. To me and probably her, it's forced interaction after the initial conversation ran it's course.
I literally just said I have random interactions with strangers all the time, I'm not afraid to engage people or rejection. Why do you keep harping on rejection especially if I don't know this person so there's no expectations on either of us? What I think you're not getting is no matter how great the interaction, some things have a start and an ending, requiring nothing else from either party, and that's ok.
I have two example of a random conversation progressing to contact information/interactions after the initial conversation. I went to Ulta and had a great conversation with a makeup artist/sales associate. We talked about make up and skin care for a good 30+ minutes. We vibed and the conversation flowed naturally like we'd known each other for years. After our interaction I asked could I follow her on IG. We follow each other and I've gone to some of her pop up events etc.
Another time I was in a store, saw a chick wearing a cute dress and asked her about it. Again, we were in the store chopping it up. She showed me some pics of her recent weight loss on her IG, I said oh what's your handle so I can follow you. Easy peasy but every conversation doesn't need to result in a new bestie no matter how great it was.
My husband is the total opposite of me. He can meet people all around the globe and you'd think they've been friends for years. It's natural for him what he doesn't do is try get me to interact with people the way he would. He understands how he meets and interacts with people is not how I do it and vice versa. Sometimes we're at events and I'm ready to gooooo, my social interaction tank is full. But he's engaging people and being a social butterfly, I let him do his thing and entertain myself. Once he's done, he'll find me and we leave. I'm not on him to wrap it up and he's not on me to engage more.