Scrying

In your map somewhere you want to put , lets say, a picture of aaron :

Next to this (although it doesnt matter where you place it,. its cleaner doing it this way) you put your scrye texture selection, which you will find in Invisible - Info - Scryetexture.

Select the scryetexture, right click and bring its properties up. Now look down for scryetexture and click on it. You will be given 2 options, one for the base texture (which is the normal texture),. and the scryetexture (which is usually the creepy version of the texture). Examples of these you will find in the package manorpicsH.

Now we've set that up, we need to put a scryehint trigger near to the picture itself. Goto Invisible - Trigger - Trigger - ScryeHintTrigger.

Now place the hint trigger near to the picture as shown.

Now when testing your creation, your gelziabar stone will go all crazy and upon scrying will change the picture to the alternate one.