What are the image cropping restrictions in the Editor?

In the Editor, when adding an Image to the “Playground” plugin, you can crop the image to fit the article body. The cropping area ratio is the fixed value equal to 16:9 for horizontal cropping , 2:3 for a slim vertical, 3:4 for vertical and 1:1 for square. 

For Cover Images- only the 16:9 ratio is available.