Okay, from those two screenshots Google Webmaster Tools:
- Does not show any error or warning (screenshot 2)
- Shows it is an image sitemap (screenshot 2)
Out of 1199 URLs in the image sitemap it states it has 548 in index.
Given Google Webmaster Tools acknowledges it is an image sitemap (and not normal XML sitemap), my take would be it has verified about half the images to be in its index? (Although the
indexed numbers in google webmaster tools in general have weird behavior.)
I would wish Google would list "indexed" images separately from URLs since it can be hard to determine what exactly is meant by indexed numbers (which already can be proven flaky in many ways, see link earlier)... But I think Google associates a page URL to an image. Thus if Google verifies an URL to be indexed in an image sitemap it includes the images associated to the URL.
But I will try dig up if there is some clear documentation on this, but I doubt it
