Hi
What problem with images do you have?
Seem that url for images are not rewrited (have some like pagespeed.CC.HASH in the url) but that normal because the images are loaded by some javascript, so pagespeed has a limited functionality in this case, images are only partialy optimized by IPRO, a in the fly optimizer that don´t change the url.
I see it is workin because the Etag header is changed ti some like etag:W/"PSA-aj-1INdW4cleQ", this header is set by IPRO.
To better test, make a pure html page, with images, and css and then test it.