How are 'down' and 'feather' written in the padding description different?

Both down and feather come from ducks, but they are from different parts of the body. Down is the downy undercoating found on the chest and belly; without a rigid quill shaft running through the center, it spreads out in all directions like a skein of thread, trapping air in between. Feathers have the shape of a feather as we commonly imagine, with a quill shaft running down the center and strands extending to both sides.

The filling of BASIC PUFFER PADDING_PINK Basic Puffer Padding Pink is labeled as 11% down and 89% feather^[2]. Listing the filling separated into two items like this is the standard labeling practice when using a mixed filling of down and feathers.

The ratio serves as a clue to gauge the character of the garment. The higher the down ratio, the greater the loft volume at the same weight; a higher feather ratio makes the property of bouncing back after being pressed more pronounced thanks to the resilience created by the quills, while also giving it a tangible weightiness in hand. However, feathers with quills can poke their tips out between the weave of the outer fabric, so rather than pulling out protruding quills, it is better to push them back inside.

hmmm, labeling that separates the filling into two names rather than lumping it into a single line is close to information meant to let the buyer gauge for themselves which set of qualities the garment leans toward.