New Fluttershy is an aggressive alter of Fluttershy’s, who seems to be coaxed out by the perception of Old Fluttershy being in danger or unable to handle the situation. New Fluttershy exists to protect Old Fluttershy, and even more importantly, to be proactive. New Fluttershy is the Fluttershy she wanted to be when she was scared. The one who solved her problems on her own instead of hiding.originally lacked a name before Rarity accidentally suggested one; New Fluttershy. As she’s meant to be Fluttershy, but better, the name suited her needs perfectly. She’s the New Fluttershy, the better one, the one who doesn’t take anyone else’s crap.

In case you don’t understand why she looks different than Fluttershy, alters can have a completely contrasting self image and identity, reported age, gender, general knowledge, most things. It means that most likely New Fluttershy perceives herself differently than Fluttershy’s physical appearance is.
She definitely identifies as a female pegasus, but is also probably somewhat different. But going under the idea that New Fluttershy is an idealized creation of Fluttershy as a filly, she does resemble Fluttershy’s filly state slightly. Fluttershy imagined what she’d like to be as a strong adult, but didn’t have much to go on, meaning that New Fluttershy lacks a cutie mark. Of course, New Fluttershy’s perception of herself affects her mental appearance, so she deviated from the original idea. But I based her mane off of Filly Fluttershy’s, in that she didn’t comb her mane to one side and had simply a long forelock. She has the wing model of the average stallion and her model is more buff than the average female. She also has a singular eye shine, much more common in male ponies than female, representing strength and masculinity.

Her colors come from using Fluttershy’s outline as a fill for her coat. Her mane is the color of Flutterbat’s eyes, and her eyes are the color of Discorded!Fluttershy. She took bits and pieces of things to make her own identity…. whether or not that’s really her own, is debatable.