To measure user experience (UX) you need to understand the stakeholder journey.
To understand the stakeholder journey you need to understand what the stakeholder is trying to achieve.
If you focus on making it easy for the stakeholder to achieve their goal you will have a good UX.
If you remove the stakeholder frustrations when they are on their journey to achieve their outcome you will have a good UX.
The graphics and visuals are meaningless if the underlying journey is not easy and as frictionless as possible.