Solved! Go to Solution.
I'm not really clear as to what is meany by "index"... however, what I have found is that the Display Name value seems to be ignored and the session property shows up in the user session with a label that is identical to the value that I put into the "key" field.
Key is, as you already notice, the field name given to the detected values.
So if we got a "market" variable the key could be "detected_market". So when you search the string or double object in the session that would be it's name. detected_market = 3 or what ever. Is a required field.
I didn't actually try the "Display value", maybe is something as an alias for the key, idk. You also can't create a key, delete it and then create it again. Since an error will show that the key already exists. That is when i understood the meaningn of the fiel. Sadly it take me 3 session properties to understand it. It's a nice really addtion. Hope it reaches the Mobile app also.