Passenger Power Mirror Repair
With all respect to Doc (I've owned & operated a glass shop for 14 yrs), you've lost the backing plate & the glass. Backing plate has sockets for the screw adjusters & a ball or socket to match with the ball or socket in the mirror head. We get this all the time. Without the plate you can't even attach the glass (mirror) to the mirror housing. And if you could, you couldn't adjust it. Have never checked with Toyota to see if they can provide individual parts for a mirror head, but no other manufacturer does.
Doc is right that any glass shop can provide the mirror. However, according to Federal law, they are required (classic cars excepted) to sell you only mirrors with anti-glare coating. We sell Burco replacement mirrors, distributed by PPG, in both flat (driver's) & convex (passenger's) for $32.25 installed, with tax.
So you're probably looking for a used mirror head. No matter if the glass is cracked/gone. Make sure the plate is attached to the adjusters & pivots correctly.
Email me if you have any further questions.