Or rather, it could be that Minori isn't ready to consider Ryuji's feelings for her. She's uncomfortable with it, but cannot show it, so puts on a happy front and changes the subject.
It would be very, very weird and embarassing to suddenly talk about love out of the blue, so since the two are on that topic, they used a more subtle expression for love so they can speak more comfortably to each other. That's my interpretation.
