The abseil chain...are there (chunky looking) carabiners there permanently? Looking at a video of a guide taking a client down and it appears there are two in-situ biners as the guide looks to conect his rope into them after another party retrieves their rope.
I think when I did it nearly 40 years ago that we may have just put the rope round the chain. Or maybe there was a giant maillion. Anyhow, there's nothing to worry about because that anchor is always very well maintained by local guides, etc, because the route is so popular.
When I first did it (rather more than 40 years ago) there was no chain but instead a large collection of old slings. Everyone had make the choice between adding to the collection or just trusting what was there already!
Lorraine McCall began her attempt today at a continuous, self-powered round of the Grahams, a four-month tour of upland Scotland combining walking and bikepacking. If successful, she'll be the first person that we know of to do it.