What I think Sparky means is that there isn't really a subject here. You've got the scene, but nothing is happening. The graffiti isn't being emphasized as the subject. There are lines leading away from it, making it hard for the eyes to comfortably rest upon them. The compositions are a bit busy, if you get my point.
In #1 you've also got some weird thing sticking up from the street that's super annoying. In my humble opinion, #3 is sort of nice. The person makes ALL the difference. Now there's a story here, hidden. Now it's up to us to figure the image out. The person adds a dimension that the other ones lack. the birds in #1 doesn't do the same for me. I prefer street shots in black and white, but that's personal taste.
True; in the images graffiti's are less prominent...and an easy solution was to change the caption
The +bird image and + walker images would have been classic, if these things were distinctly illumined to make them the central concept of those images; further the graffiti seen here are not that impressive as compared to many other graffiti works i have seen in this forum( but that, by no way is your problem )
Your edits/exposures are inconsistant as well, in a way that doesn't quite work. Graffiti can be fun to shoot, although taking another artists work and framing it/shooting it in a way you find intriguing can be difficult.
I came hoping for a Martha Cooper style conjoined image/triptych. I wouldn't say it's a conventional triptych. It is three related images but I wouldn't necessarily say that they worked together to create a story or a single harmonious image. Because of that I wouldn't crtique them as a triptych.
They could work as local documentary. Out of the three the third is my favourite; you have a line leading down to the man on the left, you have interesting dappled lighting and I simply love graffiti.
I did a project about graffiti in Blackpool, I used my Lubitel with Fuji Provia 400x. I used a Mamiya as well but that wasn't as fun!
Picture 1 that concret post sticking up the foreground doomed the picture from the start. Add the pigeons, and you have three different elements competing for my attention. Picture #2 seems more of a wall shot that just happens to have graffiti all over it. Picture 3 does a nice job of bringing the man walking down the path and the wall together, but there is too much background in focus. Next time try for a lower angle to have more wall.