Barry, you can edit your picture to make it more square. The problem is the length. Medium will only show a certain portion of a picture if it’s too large. It shows up when readers click on the story but it has to conform to Medium’s guidelines or only parts of it will show in the intro.

It is odd that an Unsplash picture wouldn’t fit, since that’s Medium’s go-to photo source, but there it is. I try to choose horizontal pictures rather than vertical for that reason.