Slide Designer

As I've been searching for my employment with keywords I've discovered jobs I couldn't imagine exist:
You are telling me someone can be employed to create and develop a design bible for video-projected slides, and help everyone in the teams to use it correctly.
Right now I understand this. My first surprise is they ask for a specialized profesional where I thought that every graphic designer could do it.
Mostly this is a long term contract! You would have your career just to design and redesign slides? How would you occup your working days? That's really questionning my knowledge about my skills! .