Longer content download times on some images

I’ve built a small test page with several small images all around 5k. The test result for this (across the Atlantic, with DNS cached) is here http://www.webpagetest.org/result/151003_V3_SS1/1/details/

Several (5) of the early images always have a longer blue (content download) bar. If I build a longer page with more small images each also around 5k. The same thing happens.

So I am wondering if the longer blue bars are actually content download or in fact something else?

Thanks, Paul

P.S. webpagetest.org is an amazing site , thanks for making it!.

I’d say that you’re seeing your virtual site being woken up. I did try to repeat your tests with a few iterations ( expecting not to see such a delay on the first few images on subsequent page loads ), but you’ve taken the pages down.