HELP!!! What does this irony mean from A Cold Greeting by Ambrose Bierce: "It had been taken a week?

It is a most short story and is easily readable;

Irony 1)
This ending is ironic because the reader does not expect there to be evidence of the
picture of Barting without a mustache. The photograph shows that either Barting is still
alive or that he is a ghost, both of which are surprise endings. The twist at the end
surprises the reader and makes the reader wonder, like the narrator does, about the
supernatural.

2)
There is irony at the end because the picture proves that the man Mr. Conway met could
not have been Barting. Barting shaved his mustache before he died and the man Mr.
Conway met did not have a mustache and that made him look like Barting. But Barting
was dead so it must have been someone else.

3)
There is irony at the end because the picture proves that Barting is not really dead. This is a surprise to the reader because the letters say that he died four days earlier.

Hope this helps!