GIZMO is the name of the code suite, not the numerical technique. I believe GIZMO contains multiple hydro solvers, including various formulations of SPH, moving mesh, and meshless techniques. But you're right. that the simulation in question wasn't a moving mesh, it was a meshless technique.

>> No, this sim is done using GIZMO

> GIZMO is the name of the code suite, not the numerical technique.

Oops, misread that. You already know it's the code suite, not the technique. :)