Graham Wisnu-WR It depends on where you want the images to automatically resize if it is just in your menu table on the main page try changing it to

table img { max-width:100%; height: auto !important; }

My research says that is a better code for responsive image resizing anyway but stick to your version if you wish as both seem to work
I still need to see a proper test example page with a image you are trying to resize to be sure