The photo shows 2 attempts. The successful one, where the photo resist is successfully ablated. The other attempt was a failure in that the copper layer was in some places vaporized, and the cut went 1/2 way through the FR4 board.
The layer of copper applied to the FR4 is a layer of metal, and was cut.
Of course I’m not suggesting this as a method of cutting copper for any finished good, the copper was cut. Cutting FR4 would certainly not be a great idea either, it won’t go though without a lot of work, flames, and fumes.
If one is looking to cut thin metals, you can do the acid resist method.
Removing acid resist on copper has been discussed in threads before. GF staff have chimed in with interest vs concerns.