Displaying a message when a screenshot is taken
This is what Starcraft has done:
A text message can be shown AFTER the screenshot is taken and saved successfully.
Of course, the message should be in the chat box. If there's no chat box (i.e. in the main menu), then no message will be shown.
What about using the chatbox to notify the screenshots, as if it were a console?
I still prefer my idea rather than KRD's. When I press Pause key multiple times, the message can clearly show how many screenshots are taken during that. Showing an icon cannot do this, though.
More about my idea:
If the chat box is hidden, the phone icon should not be shown because of the screenshot messages. Otherwise it will disturb the player who takes the screenshots needlessly.
I'd rather have an icon appear in the corner of the screen, like the little phone indicating chat activity. That would feel a little more consistent, I suppose, though it would mean extra work to make it look pretty and not break things. An option to turn it off would of course also be welcome.