This relief is at Temple of Amun, Karnak. Neith is represented abstractly, holding the Was scepter and an Ankh
I first saw a version of this scene in Wikinson's _The Complete Gods and Goddesses of Ancient Egypt_. From there I found a reference to it in a Rosicrucian Journal (No. 1, 2007). That author gave credit to an Adolf Erman, _Life in Ancient Egypt_. I noted in the Erman book that he gave credit to a Lepsius. I tracked Karl Richard Lepsius and his book Denkmäler aus Aegypten und Aethiopien, where I found the original drawing of this (plus several other Set sightings)!|
Meanwhile, back to the subject, Set and archery. R.A. Schwaller de Lubicz shows an image with the dual god Seth-Antewy, which is Set and Horus sharing one body:
From _Symbol and the Symbolic_, by R.A. Schwaller de Lubicz, page 37
It is the hieroglyph for the archery bow!
(From Wilkinson's _Reading Egyptian Art_)
Hans Kontkanen, who visited Luxor in December 2010 has a photo of unusually active Was and Ankh, the Ankh holding a fan and the Was an archery bow.
The Was, which means power (of Set) is there to give force to archery skills.