Much like index.html is the default page, some configurations look for index.jpg to display as a thumbnail or preview for a folder.
Specific historical or technical archives use index.jpg for master reference images. index.jpg
On many web servers, index.jpg is used as a default image file within a directory. Much like index
Users often see errors like "index.jpg already exists" when software tries to automatically generate a thumbnail but finds a file with that name already in the destination folder . 2. Crypto and NFTs index.jpg