Yup that has to be it, if the image is indeed real.
That screen shot is super sketchy.
Doesn't make any sense for the miner to see each cluster as just one GPU. You can't just share work like that easily and more importantly it would be utterly pointless to do so.
And it's trivial to modify a miner to show whatever hashrate you want it to show.
There's also this video floating around:
https://www.youtube.com/watch?v=FGEuxwKHp5Q