I mean, I tried it out on my test board yesterday, and I see a rise of robots trying to find content. Google caught my [1.4] sitemap rather quickly.
I try it again with my pre-existing sites, it's the same result, only this time - GWT shows more detail about the submit results...
Usually, those images aren't in a normal sitemap.
Here's a typical blog sitemap... (and yes, it does have images)