"The caching of images in the end user's browser is unrelated to the way in which the images are stored on the server. When outputting a blob (including an image), Q2A adds an HTTP header to encourage caching at the client end (see qa-blob.php)." quoting gidgreen
Welcome to the Q&A site for Question2Answer.
If you have a question about Q2A, please ask here, in English.
To report a bug, please create a new issue on Github or ask a question here with the bug tag.
If you just want to try Q2A, please use the demo site.