Low score on PageSpeed/Hummingbird

I am getting consistently low scores on Google PageSpeed/Hummingbird.

So far I have installed and configured:
W3 Total Cache
WP Smush Pro

Sure, the site is much faster now yet I am still getting a low score(Hummingbird 65, PageSpeed 62)and recommended action is to "Optimize Images"? WP Smush should have fixed that issue or am I missing something? :confused: