Count the little black balls…
And yes, this is a static, NON moving image.
There are different names for this illusion, but the Scintillation Grid is probably the proper name. This illusion was found by Elke Lingelbach of the Institut fur Augenoptik Aalen in Germany. It is a modification of an illusion called the Hermann Grid, which dates from 1870.
Careful with this one – you might sprain your brain!