(On a side note: I have heard it questioned and have started to wonder myself of late, whether this practice isn't a bit too similar to the avodah zarah practices of patron saints, but that is a whole other post....)
My question to you is this -
Upon entering a New York eatery, is the sight of Reb Yeshayale a reassuring sight ("oh great... we're safe ... couldn't possibly be any mice here!") or a revolting one ("how badly infested is this place that the owner feels the need to place that photo in plain view of my table?!?!?")?