I think I know why her stare didn't affect him: because he's not an animal, her stare was about as much use as a stern look.
how make this?
Love this shot of Fluttershy when she's angry, I'll credit you in my wallpaper
At least she's wearing the Necklace of Kindness which reminds me of a request. Who wants to add the keywords "Element of Kindness"?
Her flutterstar won't work on me either.
Your Penance stare doesn't work on me, "officer". I have no soul to burn!
OMG that part made me laugh so hard.
We have come full circle. Fluttershy was more or less immune to Discord's needling and teasing the first time around, and now he's immune to her patented Stare.
Actually, i was already expecting that the stare would come...
I couldn't believe the stare didn't work on Discord! It worked on every other pony/being in Ponyville!
yes see for the stare to work the target she uses it on must have some sort of goodness in them. the stare shows you Fluttershy's disappointment and anger which cause you to worry about what she thinks about you because you want her to like you because she so adorable. If you don't care then the stare doesn't work which shows your evil thus Discord's immunity her friendship to him is more like a possession to him since its something he has never had before and he doesn't like to lose anything.