Snell's law tells you the angles when a beam of light passes across a surface from air into water or water into air. It tells you that a beam at grazing incidence inside water will be totally internally reflected. At steeper angles, light will exit into air.
It would appear that you have pointed the laser upward. The jet of water is largely cylindrical. In most places, light strikes the walls of the cylinder at grazing incidence, and is reflected back inside.
Near the bottom, the cylinder curves. It forms shapes like a stack of spheres. Near the top of each sphere is a ring shaped band where the surface bends inward. Light strike it at a steep enough angle to escape.
grazing