Earlier this year, Bieniek says he met the woman outside his apartment in Berlin.
"I want you to make photos with me. I don't want any money for this, I just want you never to ask me for my name," she told him.
She referenced a Facebook photo of Bieniek's 6-year-old son Bela with a second face painted on.
Now, Bieniek says, she shows us at his apartment unannounced and tells him to take pictures.
"She gives me a maximum of 30 minutes and after that she leaves. So I have a few ideas but I make whatever is possible," he wrote.
A month into the project, she asked him to meet her in front of Barcelona's La Sagrada Família, so he booked a flight and took the top picture of her.
The picture immediately below, is Bieniek's favorite from the series:
