First hint ... zoom in on the pics
.......... and you will see that the black embroidery detail including the blanket stitching is uneven, meaning you can tell it was not machine stitched, but hand stitched. So the person who made the top had completed it, including SBS and her black embroidery.
Then a further look, and you will notice that the LA'r has outlined SBS with a regular stitch. Most likely, that would have been done at the start along with any SITD that she did around the sashing, and such. Then she would have done the detail work, including the cross hatching.
That's all part of "custom quilting" which is what the LA'r noted that the owner had requested.
It's a lovely quilt, with lots of detailed FMQ work, that works well with the quilt top. I spent a lot of time studying it earlier, for inspiration for my own DSM FMQing!