think of a silk handkerchief and imagine trying to slip tightly into that

if you want further proof of deception do an internet search for photos of more expensive legitimate 100 silk chemise products and these do not tightly form fit to the skin either

The filler material is likely a rayon or polyester blend best guess and this is not mentioned anywhere in the description which makes it deceptive advertising and questionable about the silk percentage if there is any at all