Rashi: It is flattened out. Radak - this is like "va'Yrak'u Es Pachei ha'Zahav" (Shalom 39:3). They flatten out the [gold and silver] plates to cover the wooden image to beautify it. The exert themselves to bring good silver from Tarshish and gold from Ufaz, even though they are far from these places. Also, they dress [the images] in Techeles and Argaman embroidered professionally. All this is to show their beauty in the eyes of the masses, so they will fear them, believe in them and serve them.

Malbim: This shows that the image cannot be a conductor; it has no importance! The place of the gold and silver is not esteemed, nor are the artisans. They dress the image in garments made by people - there is nothing Divine about them!