Outfits show sleeves that are separate pieces from the main top, usually sitting around the upper arms with straps, cuffs, or little armbands holding them in place. They leave the shoulders and a lot of upper arm bare, so the look reads extra teasing when the character is stripping, posing, or getting fucked while the accessories stay on. You often see them paired with corsets, lingerie, or fantasy costumes where the dangling fabric frames tits and makes the whole scene feel more decorative and fetishy.