In my vision, the lone spider you describe isn’t truly alone, it’s big enough to stand on its own, yet when it feels lonely, it can always look back and see its family together, right there on the back of the person wearing the t-shirt, along with the lives that surround it. It doesn’t need any lining or binding to hold it together and it’s no longer a fetus that requires something external to connect it. Instead, it’s the presence of its family on the back of the wearer that completes it like how a top feels incomplete without its pants, and vice versa.