Blue (x, y) plane foliated by the set of all LOSs that constitute a cross-cut. The intersection of the plane with the tubular jet is in dark olive green. A zoomed-in view of the region of maximum limb-brightening, delimited by the dashed black rectangle, is shown at the bottom. This region has the longest LOS through the tubular jet wall (red line), as indicated by the white grid overlaid on the blue LOS plane.