No problem, thanks for your reply. I use Windows 11 with Mozilla Firefox / Google Chrome / Edge and Brave. The same issue appear on Android with Chrome or the Samsung Browser. I have a 24 inch monitor and I got this issue. My collegue use a ultrawide 39 inch monitor and she don’t. Once I move the browser windows or I flip the smartphone, the image return to the right size and stay ok. If I do this for every image of the slideshow, it will show the images in the right size. But if I reload the page, the issue return : the first image has an wide aspect ration (the original one) but the others will be squeeze to be 4:3.