High Res Image feature was introduced with OM-D EM-5 MkII in February 2015.
The feature is only in three Olympus cameras, E-M1 MkII, E-M5 MkII and Pen-F. The only diffence is that in EM-5 MkII high res image has maximum of 54Mipx while the other two has maximum of 80Mpix. E-M1 MkII and Pen-F have 20Mpix sensor and the E-M5 MkII has 16Mpix sensor. That makes the difference.
In the video my example was from OM-D EM-1 MkII. The control settings for High Res. Image are can be found, as shown in the video, in the Shooting menu 2 in all three cameras.
In E-M1 MkII to turn the High res. feature option on, go to:
after its on it can found in the Super Panel as an option:
If you havent seen the previous episodes I recomend you to watch them. The whole Using Olympus playlist can be found here: https://goo.gl/9cPqo1
If you have any questions please ask them in the comments!