Thanks!
I think how important this chapter is all depends on what OL-san does with that thought. If it doesn't lead her anywhere then it was just a passing thought and means nothing. If it leads her to be concious of him, and wonder what he thinks of her, then makes her think about have some sort of relationship outside of seeing him at the combini, then it will be something important.
I don't she has the ego to think she is anyone very meaninful in his life.