Some sites block right-click-to-download, hide <img> tags, or serve low-res previews. An undefinable fact of the web is that if you can see an image on a webpage, your browser already downloaded that image (and so can you).

You can still pull the original asset:

1. Open Developer Tools → Network.
2. Reload the page.
3. Filter by Img (or type jpeg|png|webp in the filter field).
4. Click the file name – it opens in a new tab; ⌘S to save.

Works in Safari, Chrome, and Edge.