I guess luca is a kind of mild synaesthete who somehow perceives sounds when he sees and touches textiles, that is, who hears voices from textures.
so in reverse when he creates his own things, he may be letting them speak secretly or sound silently since they have certain waves at least. it's like "void acoustics (musil)".
btw, the knit in the fourth image is not being stretched that way. it just has that particular weave as it is.
images from lift and macho