I just noticed a unobtrusive little link below the right lower corner of a photos comment box, offering "Suggest a group..."

Bravely I clicked the link, and a box opened, telling me:

Here is a new way of inviting to add a doc to your groups:
Use the "add to group" button (like you usually do with your own docs), to notify the author of this suggestion.
You can also suggest with a comment: Display your groups list.

Anyone noticed that already?

And another thing I just noticed when saving this post as draft: The link also apears here under the comment box... a little bug? ;-)