What should be the label written next to a back button? Should it be the current activity or the activity the button would take us to? Take facebook's mobile website for an example-
The label says, "All Groups" which is the current activity/display. I think that the label should say which activity it is going to point because it is just next to the back button and the user might take it as the activity back button is referring to. So, instead the label should be "All Bookmarks" or something.
Please answer to a general context and not only to this example.