Trying to see what actions can be performed with a PHP script that is being called via an image src like so:
<img src="http://example.com/script.php" />
Are there any ways of doing such things with a PHP script that is being called in the img src attribute?
No. A resource that is used as a
src for an img tag needs to output image data, nothing else.
There are some exceptions, eg. a
header("location: ....") redirect, but the redirect needs to point to another valid image resource, not a web site as you show in your example.