There seems to be a problem with indexing photos that are presented with the Image Browser. I don't believe that this is related to Nextgen gallery 2.0.x, because I also encountered this problem with version 1.9.x.
Because it is supposed to work good together with Nextgen gallery, I am using WordPress SEO. That is on the latest version 1.4.13.
For a couple of months now I have a few pages where I am displaying photos with the Image Browser. When I look at my sitemap, created by WordPress SEO, it shows me the correct number of images that are on these pages.
The strange thing is, only the first image of these pages is indexed. This corresponds with what I see in Google Webmaster Tools. It tells me the total number of images on my site, which is correct. It also shows me the number of indexed images, this number is equal to the number of pages, which means that most of my images aren't indexed.
I've also tested by searching with Google to verify that only the first photo of a gallery is indexed and this seems to be the case. When I do a Google search with the title of the first photo of a gallery, it shows up as the top image. If I Google the title of other images from that gallery, none show up!
Could this have to do with the way that the Image Browser works? When I use the Image Browser I create one WordPress page, which is added to my sitemap. But the Image Browser creates in effect different subpages for each photo, but these pages aren't in my sitemap.
Is there something I can do to fix this? Are more people coming across this issue?
Could this be considered a bug, either in Nextgen gallery or WordPress SEO?
I am looking forward to some feedback.