Well, Kaitlyn sees herself as a monster because of her low self-esteem. The overall lack of color in her [s]stand's[/s] shade's base form is a parallel to the way she thinks she lacks something essential to being human, and the progressive, monster-like transformation parallels her idea that she's, well, a monster. She's also grumpy and has the potential for blind rage, which is why her [s]stand[/s] shade becomes more monstrous as she gets angrier. Her blind rage is when she herself is at her most monstrous, and so that's why her [s]stand[/s] shade is at its most monstrous during her blind rage.

Also, her general confidence in her ability to achieve her goals is the reason why the base level of her [s]stand[/s] shade is capable of doing anything. It can go far because Kaitlyn knows that in spite of her being a monster, she can "go far" by doing whatever she puts her mind to.