I have been ruminating on this question since I saw it yesterday. I still don't think I have a proper answer... but regardless of long, short, pwp, or multi chaptered, I think if it accumulates to an impactful and emotional??? moment to me. like the journey it takes me through or has me thinking of it days later. hmm it's nothing too crazy like it just hits me in a profound way. like I'm seeing my fave character/ship in a new light. I'm seeing a magical moment. I'm seeing the tragedy and hope and love they are having in that moment.

there's no specific way or magic, but something emotional. a moment where it's like wow. I know this feeling or I feel like I'm feeling it.

MAYBE I empathize too much or something when I'm reading but I think that's one major way to get a fic through my heart!