Uploaded CC0 images from this project are in Category:Images from Metropolitan Museum of Art on Wikimedia Commons. There are about 80k of the 375k images currently online, you can recognize them by "MET" in the middle of the filenames. (We are in process of uploading rest of the public domain works from the museum website.)
To do a specific search of uploaded images, enter a search term directly after incategory:"Images_from_Metropolitan_Museum_of_Art", using this button:
You are also encouraged to create new categories of types of works in the collection, such as Korean art in the Metropolitan Museum of Art, using the Commons:Help:Gadget-Cat-a-lot tool.