When the Prince and Princess are catapulted over the wall of the Giant's castle, you can see their shadows on the "sky" above the wall; the sky is a studio wall painted blue.
In the scene where Jack mistakes the Giant's shadow for his own, the shadow is directly in front of him.
When the camera angle shifts to a side view of Jack and the Giant, their shadows are off to their right sides and cast much smaller.
All the cooking utensils and many of the other items (including wall decorations) are normal-sized (not giant-sized) in the castle.
