Follow this link to a comment (found in the notification inbox).
As of writing, it links to the last comment on the original question, which would normally be hidden.
There's a link just below saying
add / show 1 more comment, but there is no other comment.
It seems like it's not expanding the comments in a consistent way.
The UI should look the same whether I browsed to the question, and clicked
show more, or whether I clicked on a comment link to a hidden comment.