On Photo View Numbers

I was browsing my Picasa Web Albums earlier today. These are tied to my Google account and subsequently my Google+ profile. Going to Picasa shows you the number of views each of your photos have had. Now I am not sure exactly what constitutes a “view”. i f I post something on Google+ and it zips by while they scroll down their screen- Is that a view or does someone actually have to click on on the photo and open it up in your albums to view it larger than the thumbnail?

Many of my photos had a couple hundred views, some pf the newly posted had a couple dozen. One stood out out, though as having nearly 2000 views. This was the photo:

Wide angle shot of a stand of trees in autumn in Brown County, Indiana

Photo of the Day

And here, the second most viewed, but only at about 300 or so:

Line of windmills in northwest Indiana stretching out into the fields