SpaceX

It's hard to tell, but I don't think it's from IFT-6. The banana cam gave us a view inside the payload bay and the reinforcing structures look a little different.

I believe the truss that the banana is strapped to is the same as the one running along the lower edge of the OP image. But if you look at the reinforcements noseward, the OP shows a closer arrangement of three ribs with cross-braces in-between, whereas the IFT-6 image shows more regularly spaced ribs with no extra bracing. The ribs themselves look different, with a uniform line along the entire inner side in the OP, and a shallower middle segment on OFT-6. The OP's low resolution makes it difficult to tell, but I think it's also missing a lot of the lengthwise stringers that SpaceX added on the later ships.

EDIT: I may be talking out of my ass. Had a look at IFT-3 and the view towards the payload door shows the same reinforcing structures as IFT-6. So it's possible that the OP image is from farther up the payload bay, the ribs we're seeing are reinforcing the flap hinges, an area that's not visible in the banana cam. We didn't get a payload bay view for flights 4 and 5, so can't compare those.

EDIT 2: The OP image is definitely farther up the payload bay, looking at the hinge area that we didn't see in other bay views. There's no telling whether or not it's from the 6th flight, based on the publicly available images.