That Wacom Tablet looks like a lot of fun, Keep making drawings
like the one above.
At first I thought that you put the middle Steelhead way too close to the rock. But after another look I realized that your rock would only be a foot or 18" high so the fish is located right. I see way too many fishermen working large rocks in the back eddy for steelhead instead of the seems below the eddies. The type of rock you show is really the typical holding water for steelhead. It's hard to identify as it does not create a large boil on the surface but gives a slightly less flow behind the rock than river current. It's a place where a fish has water flowing through it's gills and a 360 degree visual and at least a 270 degree escape route.