I have noticed that when driving in EV mode when the car switches over to HV mode the Eco icon always lights up! Of course you can select Eco, or Power mode manually, but when it does this automatically, after the EV battery charge is used up, it keeps showing the Eco icon being lite not HV.
I think you are confusing ECO mode which controls throttle response and minimizes climate control usage (see Owner's Manual pg. 247) with the Eco Driving Indicator which indicates when you are driving Eco-friendly (see Owner's Manual pg. 268).
