All the cooking utensils and many of the other items (including wall decorations) are normal-sized (not giant-sized) in the castle.
When 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.
The makeup and lipstick on Henrietta the cow disappears between shots.
Obvious dummies are used for the catapult escapees.
The shadow of the tree that the group use as a catapult is very noticeable .
After Jack climbs down the castle wall and is on the ground, a large shadow of the boom microphone is visible, lower right of the frame.