Poured Concrete Foundation Question???

[Zedder]

They are getting ready to pour our foundation walls, so I went over to the site today to check out a few of the other houses in the project that have already been poured. Most of them have at least one area where it appears that the concrete was not mixed properly and you can see the aggregate on the outside surface (the other side of the wall looks "normal"). I've attached a pic to show what I mean. Is this a problem? If so, can it be fixed? I have no building experience and appreciate any help that members can provide FWIW, the walls are 10 inches thick...