Retail Template
Sellers can upload a maximum of 5 images per item for the retail template. The images must be in 1:1 ratio and the recommended pixel dimension is: 600px by 600px. The images should be no larger than 2MB, or else it may affect the loading speed of the marketplace.
Service and Rental Template
Sellers can upload a maximum of 15 images per listing for the service and rental template. Images must be in a ratio of 3:2 and the recommended pixel dimension is 720px by 480px. The images should be no larger than 2MB, else it may affect the loading speed of the marketplace.
Please refer to the following article regarding image resolution and their importance of it: Uploading the right image size.