Connection with humans
Its obvious that the shell people have limbs and a torso but it maybe possible if they have known about urban legends , told storys , or wrote poetry , it maybe possible if there were sexuality and family background , like staight , gay , lesbian , transgender , or nonbinary , single , divorced , widowed , or brother-sister marriage , and maybe they also have false beliefs like the flat earth theory , god not existing , the simulation theory , and etc.
Or could also have known if WE exist , as they are "indifferent" from us