Profile image (304 x 376)
A profile-sized images (304 x 376 px) is required for:
Link card image (608 x 424)
Link card images (608 x 424 px) are optional, but recommended, for:
Great imagery is an important kind of content. Use this guide to help you follow best practices for image sizes.
Each site has custom image sizes for unique pages and components, but shared multisite components share requirements.