It seems to me that the first slot (slot #1) was not used. There was no reward issued for that slot.
That is why there are only 6 rewards showing, each in a slot.
Each slot has possible rewards. That you may or may not get.
Not all 7 slots were used in this instance.
They're referring to 2 different adventures. The potential rewards pic is for the adventure "Traitors" and the actual rewards pic below is for the adventure "Bounty Hunter"
The whole thing is really very simple once you start playing adventures.