While setting up the opt-in tools and auto-campaigns, you will need to upload images at a number of places.
You can find information on which image sizes are right for which scenarios in this article.
All images should be in a JPG or PNG format and we recommend keeping the image sizes below 1MB.
Opt-in Tools:-
Visual Popup With Image at Right: Image Aspect Ratio - 9:16.
Visual Popup With Image at Top: Image Aspect Ratio - 16:9.
Visual Popup With Image Behind: Image Aspect Ratio - 1:1.
Persistent Discount Widget With Image Behind: Image Aspect Ratio - 9:16.
Persistent Discount Widget with Image at Top: Image Aspect Ratio - 4:3.
Welcome Campaigns Editor:-
For images in welcome campaigns editor, image aspect ratio is 1:1.