page speed still recommending i optimize my images after using wp smush pro

i used to have free version of wp smush, got membership today, installed wpmu dashboard and wp smush pro. on my wp smush pro setting page, it tells me all my images have been smush. When i run a Google page speed test and also test site at http://www.webpagetest.org/, it still recommends that I optimize several images on my site. Please advise.

Thanks