Why do birds love this house?

I am lucky to have many safe streets around me to walk. This house stands on the corner of one of them.

Every morning,  this house has a roof full of birds.  Pigeons,  doves,  whatever.  Houses all around it have the same kind of roof.  But no birds.  And every time I walk by,  I wonder why?  There is no taller tree dropping food on it.  So why do they pick this house? 

I have no idea.