What "jet engine" is featured in this ad that Simone Giertz made for a phone?
The engine seems quite obviously to be a Boeing T50 Turboshaft Engine variant, T50-BO-8A is a very, very close match, you can see pictures and info here:
National Air and Space Museum: Boeing T50-BO-8A

All major visible features are exactly the same, some minor parts are different, but may have been switched by current and/or previous owners.

Engine concept dates back to late 40's.

I did not add a picture here because of the copyright restriction posted on the National Air and Space Museum website.