Single Image Block via Image Options Ellipsis
Click the image to activate the image options bar.
Click the Image Options Ellipsis.
Select Add Border.
Basic Image Block via Image Options Ellipsis
Click the Image Options Ellipsis.
Select Add Border.
Basic Image Block via Manage Images
Click the Block Settings Cog.
Select Manage Images.
Click the Image Options Ellipsis.
Select Add Border.
Click Save on the Manage Images screen.
