As a pax I've noticed the CSD in his/her little office on 777s next to the cockpit. I note that occasionally she or he has to tinker with the IFE console to get the next set of videos running.
Other than pressing play on the video machine, I'd be very interested in knowing what other responsibilities this individual has.
£39K basic is a very nice salary (remember, the UK national *average* is £24K). Certainly a £39K basic salary would usually require a good degree. What qualifications are required to be a CSD?