To add an image to an information box, you can either drag and drop the image into the editor, or click on the image button in the toolbar.

You can then paste the link for the image in the URL box, give it an alternative description, set its width, height and alignment properties, and give it a caption.

You can also resize an image in the editor itself by hovering over the image and clicking and dragging on the black square in the bottom right corner of the image.