Real wool has natural variation
Real sheepskin is not perfectly uniform. The fiber, color, and density can vary slightly from piece to piece, which is part of its material character.
Faux fur usually looks more even, but it does not have the same natural hand feel.
The feeling changes with wear
Natural wool starts plush and then gently settles around the foot. That is normal, and it is one reason the slipper can feel more personal over time.
Synthetic linings often stay visually fluffy for a while, but they can compress in a flatter way.
Care should stay simple
Real sheepskin does best with light brushing, gentle spot cleaning, and natural drying.
It is not a material that needs heavy treatment. A little patience usually keeps it looking better.