The text of this 14-June-2018
astronews.com tweet translated into English via google says:
IMAGE OF THE DAY: Today's picture of the day shows the German ESA astronaut Alexander Gerst working in the Columbus laboratory of the ISS.
What is going on here? He looks like he's strapped into some contraption with hoses and wires and headphones and a massive metal contraption in his lap.
Could this be an exercise device or a biophysics experiment of some type?
edit: the tweet links to this further explanation of the image: https://www.astronews.com/bilddestages/2018/20180614.shtml which when translated mentions:
He is currently working on the ESA Grip experiment , which aims to investigate the effects of gravity on the human nervous system.
...or possibly lack of gravity?
So I suppose the question is "What is the ESA Grip experiment, and why does it require Alexander Gerst to be strapped into it?"