I made it to Freiburg alive. On my first day downtown I saw these handles on the University's church:
This is really interesting because exposed hands are a body-language-sign of openness. Take any image of Jesus you have seen; where are his hands, and what are they doing (other than being nailed to a cross)?
This of course is not true for every picture of Jesus, but he is almost never portrayed as aggressive unless the artwork is depicting specific scenes of The Bible (i.e. the cleansing of the temple).
When you expose your palms, your body language is saying that you are being open, welcoming, honest, etcetera. Compared to other things you could be doing with your hands. For example, crossing your arms, or even displaying the back of your hands in certain ways can be perceived as defensive.
Body language isn't something we think about all the time, but it is an important factor in every social situation we are engaged in. The Freiburg University Church was built between 1683, and 1701. It is fascinating that this symbol of body language was incorporated into religious artwork even then!