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How do I control the GalleryType setting when listing with ExternalProductID or ProductListingDetails?
When listing an item using the eBay Catalog feature, special logic exists for the determination of the PictureDetails.GalleryURL setting. The behavior of AddItem and which image is used for Gallery, varies based on the use of the ExternalProductID input, versus the ProductListingDetails container, and the explicit GalleryType setting. The examples below explain the behavior through examples of various combinations of settings.
When listing with ExternalProductID, the following logic applies: