I suspect that what were dealing with here is an automated file managment system that renames, reformats and saves files as appropiate, reformatting an image is really just a one click thing (save as) in photoediting software (renamed in this case to forum_image followed by an image code a series of letters a numbers) but automated of course. For Example: from: https://kinsta.com/blog/image-file-types/ "Most social media platforms (like Facebook and Instagram) automatically turn uploaded image files into JPEGs. They also use unique social media image sizes to control the resolution of your photos." and further on: "PNG is a raster graphics format that supports lossless compression, maintaining detail and contrast between colors. In particular, PNG offers much better text readability than JPEG. This makes PNG a more popular choice for infographics, banners, screenshots, and other graphics that include both images and text. Advantages and DisadvantagesHigher quality (lossless) images and clearly visible text.Larger file sizes can slow down your website if overused (especially high-resolution images).Browser and OS SupportSupported by all major browsers (Chrome, Edge, Firefox, Internet Explorer, Opera, Safari).Supported by all major operating systems and their standard image editors.Use CasesGood choice for infographics, banners, blog graphics, screenshots, coupons, and other visuals that include text.Do not use for high-resolution photos, as it will create large files of up to several megabytes." I should note I have No affiliation to Kinsta whatsoever... wink