What you want to see in a street photo is not only encounters, but what I call strange encounters. It is this strangeness that makes a picture itching. You want to have a second look. What are these people doing? Why are they there?
If the image is complex you need to connect different encounters to each other to prevent the image to fall apart in two or even more images.
There are different tricks that can accomplish such a unity. One of them is to connect sub-themes by a line structure like it is done on this image. Even a straight line will do.
There are three very different people encounters in this image: a) the pair in the foreground (which opens the image); b) the couple up left moving out of the picture; and c) the three (seemingly) gentlemen in the background in the right hand side. All of these are held together by the overall composition. They are connected by lines, spaces and directions.
The main point is that you have to, at least, capture one strange encounter at the top of the visual hierarchy through which an image is approached/opened. In this photo such an entrance are the two young people in the foreground. They seem to have great fun discussing who is going to take the picture of who.
Strange does not carry any negative connotation. The label is used simply to connote a situation that is a little different. A humorous situation being one of the options.