It's interesting how she is observant enough to be able to tell that these women really are just clinging to her, but due to her low self-esteem simultaneously is unable to make the connection why they would choose to do that.
Also, being able to tell the difference in her voice with in-ear headphones in a train when Sayuki is doing the best she can to disguise it? Sera is once again effortlessly being both impressive and scary in her obsession with her.