Maybe the best way to phrase it would be "incongruous"
Fire Emblem started with a Record of a Lodoss War art style, and it's pretty much stuck to it through it's run. That means that costumes aren't necessarily realistic, but they hue closer to reality then Final Fantasy or Shining Force on average. Knights wear platemail, sword fighters are in tunics, mages wear cloaks and robes, et cetera. If it weren't for the bright colors, it'd be fairly drab.
Awakening and Fates decided to jazz that up. Practicality was given a backseat to looking cool. Female Knights with boobplate and pauldrons, swordfighters in overtly complicated outfits that would be hard to slip into, Tharja. There's a lot appealing about the art, but it does come off overdesigned in comparison to all previous installments, even the Radiant Dawn era of swag promotion outfits.
Hidari's art is a return to form from the overdesigned Awakening art. Simple outfits that add a naturalistic aesthetic as opposed to the more avant gard outfits of Awakening and Fates, which look like they stepped off of a runway in Milan rather then a battlefield.