How are "salmon mesh" made?
I believe the image you are showing is of fresh-caught salmon which is on racks being air dryed or smoked. The pattern you see are cuts made in the flesh to aid in the process. The Alaska Department of Fish and Game has an information sheet on smoking and drying fish.

Cutting is done so that the fish will dry quickly by exposing as much surface area as possible to the air. In Alaska, a traditional method is to cut the flesh away from the backbone, scoring it so that folds of flesh hang exposed to the air.

This method of fish drying has a strong tradition among the peoples in the Pacific Northwest within Canada's First Nation and Alaska's Native Communities, with each group having its own unique cutting technique. This University of Alaska at Anchorage publication has an excellent overview of the process of cutting and drying fish.