I'm pretty sure you don't need the period
If Apache is up and running then the html is the problem.
Make sure the images folder exists, and that it is accessible.
In terminal try to locate the directory named images to make sure you have the right path. I'm not sure where Linux Mint puts the www, but Debian, and Ubuntu put it in /var/www. Fedora puts it in /var/www/html.
So in terminal type the following (change the path to match Linux Mint's)
Terminal should tell if it is a directory or not. If it is chmod it. I do not know if Linux mint is the same, but in Debian it is
chmod 777 * /path/to/directory
Pick the appropriate permission, and make sure the commands match Linux Min'ts format.