Well, I´m almost sure that it´s a posed pic. The AA-mount should provide minimal air and ground defence capacity during stops using one of the MGs mounted inside the tank, here the turret MG. And it looks like the soldier uses a standard infantry Type 11 lMG not a Type 91 Tank MG as the mounts for the optics are missing.
In addition there was not really enough space inside the vehicle for a reserve MG.
And another vehicle for your list:
- Type 4 Special Motor Launch Ka-Tsu (standard armament 2 single Mount Type 93 13,2 mm Machine Cannons)
The Experimental Amphibious Tank SR-III was also suggested to use the Type 92 13,2 mm Tank Gun but the whole Project was cancelled before the final decision.