Of course the land does not vote, but when people talk about political control, it is often by territorial expanse.
One of the things that such maps do show is just how easily it can be that a large part of the population is present if a very limited amount of the area. If elections were won purely on the raw popular vote, the candidates potentially would need to just sweep the high pop. density areas and they could win the country. For example, the population of Dallas County (2.28 mil), Texas, as I recall, is larger than the population of New Mexico (1.87 mil). Basically, the candidates could blow off the entire state of New Mexico if they could win Dallas County.
Similarly, the Texas population of the I-35 corridor (including municipal areas straddling the corridor) and eastward comprises well over half of the state's population but well less than half the geographical area. Furthermore, areas of DFW (5.2 mil), Greater Houston (4.8 mil), Austin (0.65 mil), and San Antonio (1.1 mil) have more people than the rest of all other areas of Texas. Texas' total population is 22.1 million.
So electoral representation is a real issue when it comes to population and territory covered. It is for reasons such as these that the House of Representatives is comprised based on population so as to help assure folks have supposed comparable representation in Congress whether they be from a densely populated area or rural. It simply was not enough to have two Senators represent each state as some states have low populations and hence get better senatorial representation per person than in more densely populated states.