The narrator, for example, visits Lineland (a one-dimensional word) and while he is a square he is perceived solely as a point because people in a one-dimensional world like Lineland only have north/ south; this in contrast to north/south, and left/right in Flatland, and in contrast to north/south, left/right, and up/down in Spaceland.
Similarly when a sphere from Spaceland (a three-dimensional world) visits Flatland he is perceived as a circle. Indeed, what people from Flatline understand is solely a single plane cutting through the sphere:
People in Flatland (Lineland) just can't perceive the idea of there being more than two dimensions (one dimension). Is there a fourth dimension out there that we as people living in Spaceland just can't perceive?