What I usually find appealing in yuri relationships is precisely when the author removes the power dynamics.
That one of the characters doesn't have to "take charge" of the relationship and the other doesn't has to be passive is refreshing compared to the usual tropes in het or yaoi relationships. Top+Bottom, Tomboy+Girly, Man+Woman, are indicative of heteronormativity.
Another reason why I like reversals. Because it introduces balance in the relationship.
I'm a bit sad that with Qiu Tong and Sun Jing, the latter is obviously a "male" protagonist. Would the story really change if Sun Jing was a boy? She's even almost designed as a guy: tall, no hips, no boobs. She's in male attire all the time, except in school..
Their relationship would be the same : Qiu Tong would be as bashful and Sun Jing would be as aggressive.