Last modified: 2014-11-13 17:46:00 UTC
The page title corresponds, obviously, to the page you're on. Whether you've "left the page" is somewhat subjective in some cases, and depends on the mental model you build up. For example, Facebook's image viewer does not change the page title, because it is clearly a panel on top of the current page, whereas Flickr's image viewer does change the page title because the model is that you're navigating a new page associated with the image. Given that the MediaViewer has a cross at the top right that dismisses it, and takes you back exactly to where you were, the mental model currently for MediaViewer is that MediaViewer is not a separate page, but is instead a panel that appears on top of the current page. Conceptually, I'm not leaving the article I'm reading, I'm simply enlarging one of the images in the article. As such, it's confusing and inconsistent with that model for to change the title of the page when you click on an image and open it in MediaViewer.
Change 172945 had a related patch set uploaded by Deskana: Do not change page title when loading image in MediaViewer. https://gerrit.wikimedia.org/r/172945
Since it creates history entries (the subject of another ticket/debate), has shareable URLs that take you back to the image you were on and not just to the article and takes over the entire screen, it does make sense for it to act like its own page. The titles help navigate the various history entries, in fact, so there two features are complimentary. The description of this ticket is a subjective opinion, until user testing is performed on a large enough sample, there is no way to establish which model is more universal than the other and/or performs better. You can be sure that if it was implemented the other way around, we'd get a bugzilla ticket asking for it to be the way it is now.
We're planning on user testing different history strategies at some point in the future, I'll make sure to include variations on the title logic when we get to that.
Change 172945 abandoned by Deskana: Do not change page title when loading image in MediaViewer. Reason: Not wanted right now https://gerrit.wikimedia.org/r/172945
