Pictures from Palestine Today might shed light on the matter. First they show the usual staged pictures of dejected people sitting in the rubble for no reason except to look dejected for the photographer:
That wasn't sad enough, so the photographer had to move to a new angle and repose his subject:
Then we get to the inside of the poor, destroyed metal foundry.
Hold on...what is that poster above the door?
Sure looks like a "martyr" poster, complete with a photo of heroic fighters aiming their guns from the top of a building!
Just the sort of decoration one would expect in a regular metal foundry!
I'd say that Israeli intelligence did a fine job in this case.