 Like a heavy ball on a hill of air, the object will fall "down", because all the heavy water "above" it is pushing it.The attraction between objects that create depressions can be seen as 2 balls in a trampoline, which have a kind of hill between them but they still fall into each other because the "hill" at the opposite side is larger than that in the middle.You only see the depression around the object where the bend is enough to be noticeable, but it reaches the edges of the container.