Comment by kazinator

A bathroom tile is also a unit of length and area. A wall can be so many tiles high by so many wide, and its area the product, also measured in tiles.

It is just word semantics revolving around a synecdoche.

When we say that an image is 1920 pixels wide, the precise meaning is that it is 1920 times the width of a pixel. Similarly 1024 pixels high means 1024 times the height of a pixel. The pixel is not a unit of length; its height or width are (and they are different when the aspect ratio is not 1:1!)

A syntax-abbreviating semantic device in human language where part of something refers to the whole or vice versa is called a synecdoche. Under synecdoche, "pixel" (the whole) can refer to "pixel width" (part or property of the whole).

Just like the synecdoche "New York beats Chicago 4:2" refer to basketball teams in its proper context, not literally the cities.