Clicking photos sends visitors to i0.wp.com, i1.wp.com, and so forth…?

Hey guys–

I noticed that on one of my blogs when users click on some of the photos, it’s registering in the “Clicks” section of the Jetpack Stats as i0.wp.com, i1.wp.com, and i2.wp.com.

I cannot figure out what this means and why it’s happening. All of my photos should all by hosted on my own domains, so I don’t understand why clicking a photo would ever take anyone to wp.com.

Does anyone have any clue what’s going on and how I fix it?