This new feature was a request from the forums and is available in Social Gallery v2.2+. When enabled (and “Show Image Download Link” is too) it will prompt visitors to “Save Image as…” when they click download, rather than just loading the image! This is great for those of you who want to make it really easy for users to get a copy of a gallery image – wallpaper galleries is a good example.
This feature does require fopen to be enabled on your server (ask your hosting to enable “allow_url_fopen” setting as per here.) – without this setting enabled this feature cannot work. Luckily most common hosts allow this setting.
To enable this feature just turn it on via the setting “Use prompt save as… for download links” in Social Gallery Settings (under Style->Picture Bar):
… Enabling these two (provided you have the setting mentioned above turn on) will mean that clicking any “download image” link in your Social Gallery viewers should let the user automatically save the file with ease!