Specify only one side of the dimension and get a square.
Specify both lengths of the dimension to cut image to your taste.
Now, change colors on the fly, call it 'zonal color markings'?
Describe what each image is supposed to mean or do
Django Hold It is similar to placehold.it - serving dummy images, but different in other ways. Django Hold It makes offline image serving as simple as possible, avoiding lengthy installations or cumbersome setup steps.
Are you wondering of how to put a dummy image server to use for quick UI scaffolding?
You win a lot using Django Hold It, as long as it is for the best use case (see below)