I don't think the comment is pointing out the difficulty in telling whether it's meant to be symmetric, it's pointing out that the symmetric case is trivial and

I don't think the comment is pointing out the difficulty in telling whether it's meant to be symmetric, it's pointing out that the symmetric case is trivial and so any example should be really different from the symmetric case in order to serve well as an example. It's hard to picture how the climbers might have any difficulty whatsoever when seeing an example that's almost trivial.