Buck is your stereotypical anti girly-girl pony. She hates anything pink, bows, dresses, makeup, you name it. If her pal Hodgepodge is engrossed with it, just know that Buck is adamantly against it!
Though, please take notice that this is all an act. In reality she actually loves these things and quite enjoys when Hodge gives her makeovers, and finds keeping up her tough pony persona to be quite exhausting. She only does this to seem tough and rugged, she doesn't want to damage her future cowgirl backstory when she becomes a famous buckstar!
Nah, it's not dumb, she needs more bows, barettes, and hairpins! I think it's really cute how Buck actually likes these sorts of things, just putting on a tough act for her future dream of being a buckstar, and lets her best friend Hodge dress her up. Also, I wouldn't be surprised if that big pink bow is actually one of her Auntie Apple Bloom's bows from when she was a filly, and when she takes all the other hair decorations out, she seriously considers maybe keeping her Auntie's bow, you know, for sentimental reasons, and maybe cause it doesn't look that bad all by itself.
It may be a hand-me-down (hoof-me-down?), but it still looks really cute on her! I love Apple Bloom gifting one of her own hair bows to her niece since she didn't have any children of her own at the time. Buck probably really like it at the time, and Bloom just couldn't resist giving it to her.