Hi Jerome,
I like the picture and in fact I am
known to be a sucker for similar images myself.
So coming back to your question, could you have taken this picture differently? Yes of course! But it would then be a different picture and not this one. This is about capturing the moment. The possibility is that the man would retreat from the window in case you would decide to seek a better pov/composition; a few meters to the right, a few meters closer, etc. During that time, light might have changed, etc. So from that perspective, I doubt you could have taken the picture differently. You can of course go back and choose your vantage point and focal length carefully and wait for the opportunity to re-appear. It sometimes does.
As Asher has pointed out, this will look OK when printed large. I have gone to see two photo exhibitions today (one by Chema Madoz in the Dutch Photography Museum and the other one by the famous Dutch photojournalist Vincent Mentzel in the Kunsthal Rotterdam). One of the things I have noticed is that there were some pictures which contained smallish details like this one but it was perfectly OK when the pictures were printed at a size of 60x90cm or larger.
I think what will make this picture more worthy is if it would have been a part of a project (or body of work) which stand stronger together. So IMO, the way to do this one better is by complementing it with others.
Cheers,