Interplay between aspect ratio and imghist

[johnshin86]

I am not quite sure how the aspect parameter is interacting with the size of the histogram in the imghist function. For a square image, with the vertical orientation, an aspect ratio of 1.0 produces a histogram taller than the image. For a square image, with the vertical orientation, the default aspect ratio (1.75) appears to produce a histogram that is the same height as the image. What is the logic here?