Cactus sounds like a good idea, although what's happening here is with the flow of your wall material. The layout of the scene tells us there is an inside 45 degree corner, yet the material disguises any hint of a corner. If you place a vertical support beam imbedded in the stucco ( a large vertical crack would work too), it'll allow your poncho and whatever else is on the shelf to carry the viewers eye. Nice scene! ICM my .02

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Ockham's razor- It's that simple