It depends on which changing portrait you're referring to. If you're talking about the one in the Foyer of WDW's mansion, it was achieved 2 ways. The first way, the way they achieved it prior to the 2007 rehab, was that they had 2 slide projectors behind the wall with the slides featuring the different "stages" between Master Gracey, which would cross fade between each other in perfect synchronization. The 2nd and currently used method is that it's now digitally animated. Which is a much smoother effect, and much clearer too. If you're talking about the portraits in WDW & DL's Portrait Hallways, the effect is different for each one. In WDW, they're once again, just like the foyer portrait, digitally animated. In DL, they have 2 layers. The 1st "stage" consists of a painted scrim (theatrical fabric material) containing the "normal" stage. The 2nd "stage" is another painted scrim, containing the "ghastly" stage. When the lightning flashes, there's a white light from behind the 2nd stage scrim that illuminates the painted scrim, since scrim is a material that is opaque went lit from the front, and transparent when lit from behind. OR, if you're referring to the portraits in the Attic with Constances' husbands, those are also digitally animated. Hope this helped/answered your question.

Last Edited By: DreVog Jan 5 13 1:16 PM. Edited 1 times.