Yes ducks do remember faces.
Ducks have the ability to remember someone they've seen before and if you go see a duck enough then that same duck will remember you.
My friend has a duck and whenever I go to his farm that duck always remembers me and comes right up to me and even lets me pet it.
The ducks when they don't know you at first will tend to shy away but as the ducks get used to you then they may allow you to touch them or want to stay close to you.
The duck always seems excited to see me and will come up to my truck well before I get out of it and will stand by the door looking at me while I get out of the truck.
Then he will follow me around and not leave my side until I leave.