This is a quite obscure flag that little is known about. I can’t even say that it is rotated the correct way and shouldn’t be lying down instead. However, I couldn’t help but opt for the funnier rotation.
The flag was possibly not in widespread use, or only used briefly. The more commonly cited flag of the Buchara Emirate looks like this:
The only source seems to be that some guy named Ivan Sache’s parents saw this flag in a museum Buchara. There was no caption, so it’s uncertain how this flag was used, or even how it should be rotated. There is a low-quality picture showing it displayed horizontally:
However, it does not seem implausible that the hand of Fatima would point upwards, as it normally does. If there is no red border at the bottom, which cannot be seen, it would seem logical that that would be the hoist side. And not the least, it would definitely be more amusing if the flag was rotated this way.
Northern Ireland but Islam