I like what Dan did to that pic in Photoshop. The Prisma filter, not so much. That made it look like someone tried to make a lithograph while on acid, though in fairness, Dan obviously knows a lot more about what works in a GF than I do. My own $.02 as a photographer would be that if you followed Dan’s steps in Photoshop using the original image, you might get better results. I assume that what we see here is a reduced image, and that your original is in much higher resolution. You’d get less .JPG artifacts that way, and some selective application of the blur tool would help reduce the ones that remain.
Although I haven’t received my GF yet, I do have experience converting photos for use in laser engraving on both wood and glass. The operative word is always contrast, contrast, contrast! Subtle gradients and fine detail tend to fall by the wayside. You’re facing an uphill battle with this particular image, because as Shop already pointed out, the beauty in that pic is from color. It doesn’t have a lot of inherent contrast, so adding some is essential, but brings its own set of problems as well. I think JBManning is right. I have a gut feeling this will end up looking better on slate or glass as opposed to wood. But I look forward to seeing it one way or the other.