Sylvie,
On Google Earth, the golden colored Mickey is directly in the middle of the Seven Seas Lagoon, which is the lake immediately south of the Magic Kingdom. It is also the lake that the Resort and Magic Kingdom monorails circle around. If you select this golden Mickey icon, a pop-up box will appear. You will want to select the "Show Disney World in 3D" button at the top of this pop-up box.
If you still can't find it, you may have turned off some "layers" in your Google Earth program. Depending upon your experience level with Google Earth, it probably would be easiest to simply re-install Google Earth, and then the layer with the golden Mickey should appear.
The pop-up box from the golden Mickey also functions as a very helpful central navigation menu to more easily and quickly navigate to specific theme parks or resorts throughout WDW.
If there are other readers trying to figure out Google Earth's new WDW in 3D functionality, I highly recommend you start by clicking
here. Be sure to watch the short video and read the instructions below the video screen. Also, be aware that if you have a slow internet connection and/or a slow computer, the experience may be "less than magical". ;-)
Hope that makes helps. ºoº