This strikes me as a pretty ridiculous social experiment.
I wouldn't hug a stranger on the street, whether they were white, black, brown, Muslim, whatever. It says nothing about my hypothetical racial biases that I wouldn't feel safe letting a stranger physically embrace me.
This reminds me of an ad I saw on racial prejudice that showed a young white woman declining to sit next to a black man on a bus to illustrate everyday acts of racism. While I understand the intention of the ad and agree that such actions could be interpreted as a micro-aggression, I think it's crappy to shame anyone into doing things that put them in close physical proximity with other people's bodies. There are a lot of reasons that women especially wouldn't feel safe doing that. His sign says "Do you trust me enough for a hug?" and I have to say "No." Not because he's Muslim, but because he's a man and I'm a woman who lives in a culture where men are often violent and coercive towards women. I should be able to refuse physical contact with another person without being accused of prejudice.
So I don't think this piece is really all that successful at a) saying anything about racial biases or b) encouraging openness between Muslim and non-Muslim people.
What do you guys think?