Not quite: it's the resistance to change in velocity that gives rise to the concept of mass.
Historically, yes-inertia and Newton's 1st law. For the purposes of this example though, massless particles do not rest, they fly at the same speed in a vacuum. The fact that the projection "hides" a componet of their massless velocity and the observed velocity is less and could cover a range from zero, to the vacuum v in the full dimensional space. If massless particles could fly(propagate) at any speed, then the example wouldn't work as intended.