Insert Zoom Region on a Layer

I just ran into wanting to do this with layers as well.  I have attached the graphic I was given for a dictionary entry.  On the slide, the graphic is small to read each pop-out definition.  I would love to have someone click on one of the pop-outs and be able to zoom that region while he or she reads it, then closes it, and then does the same with the next pop-out.   I guess I will just have to type the text into a layer to do this for now.  Thanks-