"..Since I do banners like this for a living, I can tell you it take more than a few hours depending on the equipment. A banner that large can be done one of two ways. With a grant format printer. It would probably take about 3-4 hours to print, then hours more to sew and grommet so it could hung. It would have to be Made of heavy duty material or one that was reinforced or the sheer weight would rip it apart.
The other way it to use a smaller series of machines all color calibrated and produce sections. At that point they would have to be stretch the length of the banner ( read large facility) and sewn together. Additional support would go on the tops and bottoms.
In short if it was related Qana and went up within two hours- four hours, it was done prior to the bomb hitting. No other way. Just putting an image together that large on a computer with Type would take a few hours.
Then color tests, proofs and finally printing. That would be an all day affair for most print houses even with a grand format printer. The cost would be in the thousands.
Then you would have to transport it..."
Remember, you are dealing with the propaganda arm of the group who places the rocket launchers.
It is almost a sure bet that any site used repeatedly to launch rockets is going to become a target. Not too tough to set that up, if you deal with the people making the decisions.
Emplace your rocket launcher near the building, close enough to convince people that the Israelis did it when they struck the rocket launcher but far enough away that an attack on the launcher will not bring down the building.
Print the banner ahead of time, save up bodies from other incidents in the morgue. Make sure you have some cute kids, the more the better. Really mutilated bodies will not command the sympathy in the press that ones which look like little sleeping angels will, so keep them tidy, be selective.
When the rocket launcher gets hit, (remember, even launch times can be arranged), move the bodies in if the airstrike does not bring the building down.
Under cover of darkness, put the bodies in areas which are likely to form pockets in the collapse, and less likely to be completely filled with debris.
Detonate the charges in the building, and call the press.
When the press arrives, start parading the bodies around for a photo-op, blame the IDF, and let the MSM do the rest.
Piece of cake.