Thanks jayderyu,
I'm actually familiar with the built-in iterator for the Dictionary. I'm not having a problem with the functionality. I just think I might have spotted a typo in the text describing the functionality.
I've included some images below.
You can also check for yourself by opening a new project, adding a Dictionary, and then adding the Dictionary's "Compare current value" condition to any event. The typo seems to be in the event block text for that condition.
Walk-through:
Another example where the confusing nature of the typo might be a little clearer.