“Steady Standard” how is it used?

During my recovery ride today I had a ten minute interval called Steady Standard.

What is the purpose of this interval and what data is being gleaned?

How, as a user, can I use this information?

My AI coach, OG, told me this;

The “steady standard” interval is a controlled effort to gauge your recovery by comparing power output and heart rate—your efficiency factor of 1.3 shows you’re doing well.

Can we expand?