@Alice_Cheshire—
As an exercise, take the population of Manila given in
that article (1780148) and divide it by the area (42.88 km).
I suggest that, rather that referring to Wikipedia articles or to cities, one simply try reducing things to human scale. These days, most of us have a clear idea either of two meters or of six feet (1.83 meters), and hence should be able to imagine an area of four square meters or of 36 square feet. Now, imagine packing
2770 people into four square meters or
2319 people into 36 square feet. Granted that the campus would not be expected to have a uniform population density, but areas with fewer people per square whatever would imply other areas of still greater density.
Of course, the reported population is intended to be absurd.