Creating Spoilers In Powerpoint

Hey there,
is there a way to create a spoiler in power-point presentations? I want to include a picture but don't want it to dominate the page, so i want to have it stored in a little box that i can expand whilst i present it. If there's another solution, i'd greatly appreciate any help

This isn't exactly what you're looking for, but you could create two versions of the slide - one with the picture and one without, then use an action button to link between the two.

Like so: http://www.homeandlearn.co.uk/powerpoint/powerpoint_p4s4.html