Hi

I can see where the confusion may be as below:-

When creating a listing the seller sees the following information: -

Listings that are missing a main image will not appear in search or browse until you fix the listing.

Choose images that are clear, information-rich and attractive.

Images must meet the following requirements:

Products must fill at least 85% of the image. Images must show only the product that is for sale, with few or no props and with no logos, watermarks or inset images. Images may only contain text that is a part of the product.

Main images must have a pure white background, must be a photo (not a drawing) and must not contain excluded accessories.

Images must be at least 1,000 pixels on the longest side and at least 500 pixels on the shortest side to be zoom-able.

Images must not exceed 10,000 pixels on the longest side.

JPEG is the preferred image format, but you also may use TIFF and GIF files.

If you look at the general image standards you see this

General image standards

You will find a comprehensive list of all Amazon’s image standards specific to your product category in the corresponding category style guides. Please read them carefully as images that you upload to Amazon must conform with these requirements. Note that in the case of overlaps or conflicts, the guideline of each category takes precedence.

Images must accurately represent the product and only show the product that is for sale.

The product and all its features must be clearly visible.

MAIN images should have a pure white background (pure white blends in with the Amazon search and product detail pages – RGB colour values of 255, 255, 255).

MAIN images must be professional photographs of the actual product (graphics, illustrations, mock-ups or placeholders are not allowed). They must not show excluded accessories; props that might confuse the customer; text that is not part of the product; or logos, watermarks or inset images.

Images must match the product title.

Images should be 1,600 pixels or larger on the longest side. This minimum size requirement enables the zoom function on the website. Zoom has been proven to enhance sales.

Images must not exceed 10,000 pixels on the longest side.

Amazon accepts JPEG (.jpg), TIFF (.tif) or GIF (.gif) file formats, but JPEG is preferred.

Our servers do not support animated gifs.

Images must not contain nudity or be sexually suggestive.

Shoes MAIN images should be of a single shoe, facing left at a 45-degree angle.

Women’s and Men’s Clothing MAIN images should be photographed on a model.

All Kids & Baby Clothing images should be photographed flat (off-model).

Details can be found on the link below:-

https://sellercentral.amazon.co.uk/gp/help/external/G1881?language=en_GB&ref=efph_G1881_cont_G17811

I have highlighted where sellers can be confused with the dimensions. Also the confusing part is whether its means 1600 mega pixels from left to right or height or visa versa.

Here is another confusing part about images being RGB 255,255,255. RGB means pure white background. None of the images below are in a pure white background.

Unfortunately if the information is not clear there is more room for error.