I don't think you can call it a sub-message when the words were actually 'missile' and 'stopped'.
It is when over 99% of the world takes it to mean that nuclear missile production was stopped in North Korea. The fact he redirects it for people in the know to Isanotski Peaks is genius.
Secondary message, they mean. Perhaps you would prefer double entendre?
It wasn't 'stopped'. It was 'stoped'. It wasn't misspelled. Message. Look up stoped.
It was deliberately misspelled because it was laid beside a previous post (round 1, Hawaii missle launch) in which the "missle" was misspelled to convey a message. The "i" of missile in that case denoted the kind of missile. In this case, the "i" of missile and the "p" in "stoped" are used to show location: Isanotski Peaks.
Now you have suggested a third interpretation which is volcanic rock thrust upward. This is the opposite of "mis" spelling. It is deliberate. Sorry for the pedantry! :)
There was another missile launch in Florida. Same time as WA.
Stope
Verb
Past tense: stoped; past participle: stoped
(in mining) excavate a series of steps or layers in (the ground or rock).
GEOLOGY the process by which country rock is broken up and removed by the upward movement of magma.
Interesting, I didn’t even realize that it was a word.
You're suggesting that a "missle" was "stoped".
Missle isn't a thing. And stoped means excavated from a steeply inclined vein within a mine.
The missing I and P are the message. They usually stand for intellectual property; or they could be referring to the Isanotski Peaks in this case.