Fairly straightforward. If you use the selector that way, it would only get that specific image from that 1 page. Take a look at this example which I created manually; it will grab the first 3 images. You can easily create more image selectors by incrementing the nth-of-type to 4, 5, etc:
{"_id":"miele-test","startUrl":["https://www.miele.pt/product/12537200/maquina-de-lavar-roupa-de-carga-frontal-w1-wwi880-wcs-125-gala-edition-branco-lotus"],"selectors":[{"id":"Title","parentSelectors":["_root"],"type":"SelectorText","selector":"h1","multiple":false,"regex":""},{"id":"Image1","parentSelectors":["_root"],"type":"SelectorImage","selector":".hls-product-gallery__tile--large img","multiple":false},{"id":"Image2","parentSelectors":["_root"],"type":"SelectorElementAttribute","selector":"div > section.hls-product-gallery__wrapper > div:nth-of-type(2) img","multiple":false,"extractAttribute":"src"},{"id":"Image3","parentSelectors":["_root"],"type":"SelectorElementAttribute","selector":"div > section.hls-product-gallery__wrapper > div:nth-of-type(3) img","multiple":false,"extractAttribute":"src"}]}