The Kosher store is not recognizeable as a Kosher store. According to your reading in Tosafos, that Tosafos means that the Issur and the Hetter has to be visible, it would have to be visibly clear that this store is Kosher and that one is Treif.
As Tosafos in Gittin put it, it depends if there is an Iruv. When you are looking at a group of people you aren’t seeing an Iruv. You see the people as people. When you aren’t dealing with individuals then the theoretical person is Battul.
I mentioned how you naturally look at it because that can be used to draw the line.