On a very tall or very wide image, the cropping tool (for Instagram) will cut off the edges of the image.
For images where you don't want to crop off any portion of it, an option to be able to "fit" the full image inside the canvas would be super helpful.
(In CSS-speak, similar to background-size: contain, vs the current functionality which is background-size: cover.)
An alternative would be to allow me to "expand" the canvas by dragging crop handles, as demonstrated in this image, filling it with whitespace.