I am thinking maybe this is a missile targeting US airbase for bombers in alaska or australia.Very unlikely. A missile of these dimensions likely weighs 10 tons. Possibly a ton or so more with the structure holding it up.
Considering that likely weight of YJ-12 is likely around 2 tons each, there's simply not enough lifting power to do it all.
It's likely this big missile configuration is also very draggy, so the last thing needed is more drag.
Besides, a mission that includes both attacking a ship 2000+ km away and attacking ships 500 km away, from a single plane, is more or less impossible to imagine. If such a need arises, it'd most likely be done by two sets of platforms.
If you look at the picture from "Naval and Merchant Ships" Oct issue, the AL- AShBM is much shorter than DF21d.