That's a solid 8, maybe 9 in person. Here are areas for improvement:
I don't like the black glob on the right hand side of the second slice from the bottom.
Try to size your brisket for the box before cooking. That will allow your bark to wrap around the sides. Not essential, but I think it helps appearance as opposed to trimming after the cook.
It might be the lighting, but it looks just a touch dry.
It's a meat contest, but try to even out the parsley on all four sides. It's a little uneven on the top and right.
Overall, that's a really good effort for a first time.