Thanks for bringing this up; as of now, images can get rounded off corners by double-clicking on them and selecting the rounded square option. This process will crop the image corners and make it round. However, if you're looking to control the amount of curvature, I'd suggest you post a feature request for it here: https://adobe.ly/3K9IUfF and let our product team know about this requirement. They might reach out to you asking for more details on this.