Struve 142 in the lower left corner.
Also, shows autoguider FOV relative to primary imaging camera's FOV.
Note, the autoguider does not need to be parallel and aligned with the telescope.

But, when it is, one of the advantages of a separate guidescope is it can track on a comet or asteroid, which an off-axis guider (OAG) cannot do, unless the object just happens to be in the same field of view, which would be rare.