The dynamic process of the interaction between a jet flame and a lateral wall is experimentally studied. The evolution of the outer buoyant vortices, which are involved in the jet flame bulge and flame tip-cutting phenomena, is found to play the central role in the flame-wall interaction process for low speed jet flames. The flame response as the lateral wall approaches from infinity can be categorized into five characteristic stages based on the ratio of the flame bulge size on both sides. As the wall approaches, the flame is observed to first increase in the size of the flame bulge on the wall side. Then, flame is wiggling with off-set flame bulges on both sides. The flame is then seen to incline and attach to the wall, and finally flame on the wall side is complete quenched as the separation distance is further reduced. These variations in flame structure are closely related to the retarded evolution of the buoyant vortices due to the wall and are scaled and explained based on similarity as well as the induced strain rate due to the variation of the outer vortices.