During the Q&A portion of a Google Search Central Office Hours Hangout, John Mueller was asked a question about portfolio style sites with thumbnail images, and full size image pages.
These thumbnails are used as the navigation, and they are approximately 10-30 thumbnails displayed in a gallery-type layout.
They expand to full size when clicked, depending on the CMS plugin that’s used.
The full size image may or may not be included in the actual page HTML code.
One example the SEO professional shared was having a kitchen url showing a portfolio.
The plugin features a function where you can load “kitchen?image=123,” and this will load exactly the same page.
Their question was whether or not John would advise that they consider each image as having its own separate unique page and listing it in a sitemap. Or, should they canonicalize all of these images to the main kitchen page, and list only the main kitchen URL in the sitemap, because in reality, there is only one HTML page there.
John answered that, in general, he would treat these as unique pages.
By doing this, you can go in and see exactly what Google saw when they crawled the page.
John also expounded on the fact that, if you care about image search, you definitely want to have a separate image landing page.
He also added that for image search, when you have a separate image page with some smaller information displayed next to that image, it’s really useful.
This is something that Google systems can recognize as being a good image landing page.
But, having a unique image landing page is something that does help when it comes to image search.
Otherwise, if you just have a page that’s basically a portfolio of 30 images, and someone was actually doing a search for a query for that landing page, it’s hard for Google to say that the page has the information you need because of all these images.
The thing about image search is it works entirely separate from normal web search, and not every site cares about ranking in image search.
It is also not at all the case that if you perform well in image search, that you will have better performance in web search. Both of them are completely unrelated.
This happens at approximately the 25:06 mark in the video.