The x-ray wand (much smaller than the real thing) lets you look under the surface layer of paint on a painting. In the Forgery Lab, scanning each of the 5 paintings will show one that has other drawings beneath the paint. (That would be the real one.)
Later, when a package arrives at the museum, use the included scanner - pass it over the Starry Night copy to see the hidden message.
It will.
you have to take the underground tour
Counterfeit IslandNo, Counterfeit Island is real. In fact, it'd be better named as "Art Island".
She warns you that there is a notorious thief at work on Counterfeit Island, and gives you the key to the Inspector's house in the Country Side.
there is no mansion on counterfeit island
You do not die on Counterfeit Island.
You have to x-ray all of the paintings, and only one will have old drawings underneath the new paint, possibly indicating it is a fake painted on old canvas.
There is no camera as an item on Counterfeit Island.
You don't. There is no reason given for why it doesn't work, but it is not part of the quest.
You will have to swim for it : the lighthouse is on Big Nate Island, not Counterfeit Island.
You have to x-ray all of the paintings, and only one will have old drawings underneath the new paint, possibly indicating it is a fake painted on old canvas.
you go back on counterfeit island