Stella is pitiful
Everyone keeps comparing Stella with Ilya.
At first she is jealous of Ilya, and angry because everyone keeps comparing them, yet she doesn't pull Ilya into mud like other jealous person do.
She did her best, she tried to improve herself, by dieting, using latest clothing style, and more which is great.
But when she did her best, she is still below Ilya. No one see her or appreciate her. It's distorted her until she become like this.
She needs therapy or supportive friend.
If she have a support system, I think Stella will ignore the comparison, or even become friends with Ilya.
I hope she realizes it soon.
While the fiancé is irredeemable.