This diagram is about the human experience of space and time in the physical world. It shows a rectangular area between two axis. One is about time, the other about space. Both range from very small to very large. Inside of that area is a much smaller rectangle. It is about 1/16 of the size and labelled “Human experience”.
https://cdn.masto.host/vissocial/media_attachments/files/112/134/617/413/665/465/original/cde8b3050f5e0372.png