I have improved the right click and save behavior. It will now save as the original filename and not the long name. For example the image posted above currently is _var_customers_webs_elkarte_community_cache_img_cache_597563c0eada13027d38a842a2addab3
and now it will be notizia_nuovi_servizi_digitali_certificato_vaccinalex.jpg
That of course is the cached version not the original and prevents the cached name from showing.
As for opening the image in a new tab I see
https://www.elkarte.net/community/imagecache.php?image=http://www.regione.lazio.it/binary/rl_main/tbl_news/notizia_nuovi_servizi_digitali_certificato_vaccinalex.jpg&hash=597563c0eada13027d38a842a2addab3
I'm not seeing the cached name, was there something else you were doing?
Also If we want to go all JS on this, I can fetch the cached image, async, and set the src as a data url. Then when you open the image in a new tab all you would see is data:image/jpeg;base64,/9j/4AAQSkZJ..... I have that on my local as well. That is nicer than seeing he imagecache.php stuff (Just called in the background via JS instead) All depends on what everyone would like.