A similar thing happens for a tube open at both ends, in that reflections of the sound at both ends produces a large-amplitude wave for particular resonance frequencies. For the standing waves, an open end is an anti-node (maximum amplitude point) for displacement.

As we learned previously, the pressure change in a sound wave is 90° out of phase with the displacement. The simulation shows a representation of the displacement - the pressure change would have nodes where the displacement has anti-nodes, and vice versa.

In addition, the simulation shows a transverse wave - a sound wave is, of course, longitudinal. It's just easier to represent it as transverse.