The graph seems to make more sense for a non-symmetrical airfoil.
1 is clearly a negative angle of attack
2 is no lift but slightly more drag than 3 ... hmm
3 has lift but a little less drag. Non symmetrical airfoils can generate lift at 0 Angle of Attack, so 2 probably needs to be at a slightly negative AoA for zero lift. This accounts for the higher drag.
4 is best lift to drag ratio
5 is a higher Coefficient of Lift but proportionally higher drag, which means higher AoA to compensate for slower flight (or higher wing loading, such as in a turn). Point 5 would be at what is known as "stall speed" (really stall AoA).
6 yes, this is stalled