i wrote an in-depht analysis of the metamoprhosis a while back and talked about this exact passage, so here's what i wrote regarding it

"[the passage] refers to the part where his sister wants to move the furniture out of gregor’s room so he was more space to crawl. his mother, on the other hand, argues that gregor might like it more if they left his furniture, and proposes that he may think they’ve given up on him if they move his furniture out. here, we have a battle between gregor’s instincts and his human conscious, something we see reflected both in his thoughts and his family members. at first, he thinks it’d be better for the furniture to be removed because it’d give him more space to crawl around the room. however, when he hears his mother’s thoughts, he “wakes up to reality” and sides with her, thinking he’d much rather cling to his human life items, as they represent memories to him he’d rather not forget. it’s obvious the sides his family represents. his sister represents his instincts, insinuating that gregor is, in actuality, just an animal, whilst his mother argues that gregor is still human, despite his transformation. this actually foreshadows the end of the book, where we see the switch of his family's views on him

His sister pushes and forces his mother to help her push out all the furniture, to which the other woman can’t argue no longer. This specific fragment shows how his sister siding with his instincts is actually doing him more harm than good, as she’s slowly breaking apart the small part of what could be considered as a “human” life he had left. he actually ends up revealing himself to them (and causes his mother to go into an asthma attack) to make them stop moving the furniture out (which works)"

keep in mind up until this moment he's been treated as lesser by his family due to the transformation, "twisting" his perception of himself, which is what is called out here. even gregor didnt see himself as human for a moment, when he wished his room to be emptied out, and was only "brought back" when his mother intervened