For me, novice I am at this thing called "street," the ambiguity is simple:
Webster's definition without any emotional or otherattacment: doubtful or uncertain especially from obscurity or indistinctness
Can you identify the two characters? No, they are quite anonymous in detail, age, position and really, to race. Ambiguous, I'd say.
Can you identify the setting where the two figures are? Well, the obvious is a circular stairwell, but it could be anywhere, thus, again, ambiguous.
Is it a planned, or caught image? Looks caught to me or else there would have been time to do a proper exposure on the two figures. That fits at least one common denominator of every street definition I've ever read.