I have a website that shows photos accessible from a gallery section (that shows relevant photo thumbnails) divided up into pages.
On the desktop version of the site, the gallery section is divided into groups of 100 (as in 100 thumbnails per page).
On the mobile version, the same gallery section is divided into groups of 50 thumbnails in order to lower bandwidth costs for all.
Only other difference between the two versions of the pages are minor cosmetics, but the text is mostly the same (roughly 80+% duplicate content).
I'm just trying to figure out the best way to use canonical and alternate here.
I believe for the first 50 thumbnails, I can use rel=alternate and specify the same page number but on the mobile site and use rel=canonical and specify the desktop version of the page (that contains rel=alternate).
Now how do I handle thumbnails 51 to 100? do I specify on the mobile site via appropriate rel=canonicals that thumbnails 1 through 100 belong are associated with page 1 on the desktop site? or does rel=canonical only work if the thumbnail count is divided evenly on both sites (example: the dekstop site has 100 thumbnails per page and the mobile site has 100 thumbnails per page)?