It is very common for the street picture to have some details by pure chance. Photographer did not have time to notice them and he paid attention to something else. These details could make image stronger or weaker depending on your luck. Sometimes accidental details create or destroy whole composition.
I walked along Millennium Park in Chicago. I’ve seen children play in fountain and made a quick shot. I did not have another chance because some tourist moved to my frame. Image of children playing with water became cliché. Yes, they are cute and there is a lot of movement. I did not have much hope for this image but when I looked at home I’ve noticed woman on background. I’ve cropped to have only children and lonely figure of a woman. Woman’s gaze created another meaning of the whole photo. This is was very lucky detail.
Candid Street Photo 
keep shooting and you will find that accidents happen less often (grin)