This is something that requires added clarity. Thinking about @dchen's questions I have come to this:

• On Wikipedia
  • Can only view annotations
    • By hovering on the image
    • By using the list of annotations below the image
  • An action to add annotations (which will take the user to commons)
• On Commons
  • View annotations
  • Edit annotations
  • Add annotations (which is also a state that'll be automatically activated when coming from the 'add annotation' action on Wikipeda)

The edit or add and view states on Commons don't look very different in the gadget, or in the current design of the prototype. This might confuse users, especially when if they click Add annotation… from a Wikipedia article and are taken to the add interface on Commons. Instead of having just a small notice on top guiding users to add an annotation, making the entire page dark (or something) might be a good cue to the user that they are in a different state of that page. Here is a crude example:

Normal/Viewing	Edit/Add

@Pginer-WMF, thoughts?

I agree that exploration of annotations and adding new annotations are two different scenarios. It definitely makes sense to communicate when you are altering the existing information.

How much to distinguish viewing from editing modes? Darken the entire page is an option, but there may be more. We need to consider several aspects:

• Which is the right balance between clarity and non-distracting. We can communicate the mode outside the image, on top of the image, in the image borders, in the tools around the image, inside the image, etc.
• Whether the user may need some of the information we are hiding to add the annotations.
• Whether the user may need to check other annotations to create a new one. that is, is editing only for creating or also for modifying/checking existing annotations.
• How we communicate the way to switch between edit and view modes (especially how to exit editing mode if the user landed there).