With the metalization turned on (default setting), by setting View - Metal View - Cell Fill, the via subsections are also displayed using the pattern assigned to the via metal type being used for the via.
Each via subsection is a rectangular cylinder of current, extending between the present level to the next level above or below (depending on the direction of the via). A via subsection has a horizontal cross-sectional area equal to one cell and a height equal to the thickness of the dielectric layer. If you change the cell size, then the via is re-subsectioned into via subsections using the new cell size. The placement of via subsections is determined by the meshing fill chosen for the via.