Content Blocks > Gallery > Showcase file
The Gallery content block gives you the option of selecting a Showcase file. This is a full size image that can be placed to the left or right of a page. Just select your preferred placement - Left or Right - from the Showcase file position drop-down in Layout Options.
If you add text in the content block it will appear opposite the image. However, you can opt to display the image alone without text. Or you can add text separately in a Text content block.