I copy image link and paste it on Canvas. The images are rendered nicely in my Mac but they are cropped in iOS devices.
On Mac: Full image
On iPhone / iPad: Cropped image
If I create a card and type
!(Image URL), it does render the same in both platforms. But it takes more time than simply copy Image URL and paste directly on Canvas. I don’t mind about the border, but aesthetically speaking, I like image pasted on Canvas better.