Hello @LorraineK1 ,
Social media platforms have certain requirements for posting images, whether they force the images to adhere to them upon direct upload through their own sites, or whether they expect 3rd party systems (such as us in this case) to prevent such incompatible images from posting to begin with. I'd recommend going through this article for optimal image sizing for each social platform available via the Social Inbox tool.
When you're setting up your social posts, you can create variations, which allows you to have different wording, links, and images depending on the platform, since each has their own unique restrictions and guidelines for what they'll accept. Additionally, in the image editor under the Transformation tab, you'll find some suggested image crops you can utilize to quickly get the aspect ratios you need.
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