Rachel was putting Lorelai to the test...

Rachel was pretty much the only mature one of Luke and Lorelai's romantic interest and knew when to leave, but she picked up on the vibes of love between Luke and Lorelai right away and was definitely putting them to the test like she did with Lorelai here.

Lorelai's facial expressions and reactions show that she is uncomfortable and jealous, and that the idea of Luke becoming serious with Rachel scared her.

I also liked the similar black leather jackets as if they were telling us that Luke has a type 🤷