The only real way to make these images smaller is to compress them aggressively, or use smaller images.
Currently the transmitted images are physically much larger than they're displayed at, and are being downscaled by the browser, ( creating CPU usage as well, further slowing the load )
Front page has ~1.5MB of images which can take as much as 17 seconds to load.
Excerpt from analysis:
The only real way to make these images smaller is to compress them aggressively, or use smaller images.
Currently the transmitted images are physically much larger than they're displayed at, and are being downscaled by the browser, ( creating CPU usage as well, further slowing the load )
http://www.webpagetest.org/result/161227_0K_ZNE/1/performance_optimization/