This was done by sprinkling glitter into uncured top coat and then curing , that's why it has a textured effect
Forewarn your client that with this effect , the glitter will flake away with normal wear and tear
For a more longer lasting result that will look similar, you could do a normal rockstar nail and use a Matt top coat, or if you don't have a Matt top coat use a regular top coat and buff the surface with a a very fine buffer (like 1200 grit side of a CND Koala Buffer)