Xara's approach to naming images is awkward and is being reviewed.

In the meantime to "improve" SEO, take the Antonio 2345 image and in the Names gallery set the image Name as filename="Antonio 2345". I would do this to improve maintenance as Xara then would not rename is to nnnnn.jpg at every update, saving upload effort. One SEO possible benefit might be the churn of lots of image changes but personally I would focus on getting a clean site. Do include Alt Text that is a bit more meaningful for Antonio 2345; by all means use Antonio 2345 but add a description (like eBay).

I would avoid the use of Image > Photo Pop-up and instead use Pop-up Layers. This keeps the newly minted filename and allows Antonio%202345@2.jpg to be used, the higher resolution image.

If you use Optimise Images on the design page then the change will affect your current pop-ups and make them "fuzzy"; use pop-up layers instead.

Do not muck around with different sizes for Variants. Xara rolls all the Variant code for a page into one file. The largest image size is downloaded once and used many times, which is a trivial timing exercise.

Acorn