Right now it looks like you have a ton of 404 errors, for images.
https://www.webpagetest.org/result/1...all_view_step1
Something isn't configured right... If I go to a image from the results page, that image stays cached until I hit Shift +F5 in chrome (forces it to clear cache for a page & redownload everything as if it's never been there).
As far as I can tell this seems to be an apache issue, as I can view the images if I open them in either the webpagetest results page or if I view your source code and click that link. However, if I try to right click an image and open it in a new tab, it throws a 404 error.
I suggest you try some of these links for a potential fix.
https://www.google.com/search?ei=bCx....0.ChDRl6wSBBU