Images in a post do not show up

I’m sure I’m doing something wrong, but I don’t know what it is. I have created a small site for my wife to display the cakes and cookies she makes. [https://www.fleek.com/sweets]

When I created the “posts” for each item O had to select “Gallery” for the image to display. If I select “Image” it doesn’t show up.

I don’t have any real issues using gallery, except that if someone clicks on a post there isn’t an intuitive way to go back to the menu.