Wireless Power Coil - Is this shielding? Field shaping?
Ferrite sheet, used for flux management in the wireless charging circuit.

Ferrite has a high permeability, and therefore can concentrate magnetic fields in the vicinity. It improves charging efficiency by "focusing" the magnetic fields, constraining them to the transmitter and receiver coil vicinity. It also serves to protect other circuitry and other devices from the magnetic fields. 

I found a nice document here with a more in-depth explanation, and some nice figures which I will include here:

Magnetic flux density (simulation), no shielding:


Same setup with added ferrite sheet shielding:


The effect is quite apparent: increased flux through the receiver, and basically zero flux "leaking" out on either side.

If you search "ferrite sheet for wireless charging" you'll find loads more information.