To edit an image, select it and click 'Apply effected & more' in the settings menu.
Once clicked, a customisation window will be opened where you can crop, customise and add text and filters.
The crop function lets you select proportions for your image, or you can drag its corners to the new cropped size and click 'Apply'.
A catalogue of filters can be added to match the colour profile of your image to the email.
you can also add text to your image. Customise the font, size and colours easily and create professional looking promotional material.
Once done, save and exit and it will be loaded into your image content block.