Revealing mistake: When Luke quits Hoth, the planet is actually painted on a glass sheet but the problem is that you can see a line joining two sheets. (00:36:15)
Revealing mistake: When Yoda is training Luke by having him do a handstand and stack some rocks, watch closely during the close-up of one of the rocks. You can see a string holding it in the air. (01:08:30)
Continuity mistake: When Boba Fett shoots at Luke, he fires his blaster four times. The second shot hits the corner Luke is standing by, but in the next shot of Luke, there is no burn mark there. The only burn mark seen is the one from the third shot. (01:35:05)
Revealing mistake: When the Millennium Falcon is being pursued by the Star Destroyers after leaving Hoth, for a few seconds you can see the light of the ship through one of the Star Destroyers as the Falcon flies in front of it in the second shot. (00:35:25)
Continuity mistake: When Vader cuts off Luke's hand, as the shot ends, Luke is standing upright, but in the beginning of the next shot, he has already began to drop down. (01:45:55)
Continuity mistake: When Luke is sucked out the window, there are no wounds in his face, nor when he hoists himself up on the platform. But when he runs into Vader again, there are. (01:42:35 - 01:45:10)
Revealing mistake: When Luke runs into Vader again after being sucked out the window, as they are fighting in the control room, watch closely: Vader's lightsaber hits the wall a couple of times, but the explosions are not where the saber touches the wall. (01:45:20)
Continuity mistake: Just before Leia gives the order to evacuate and leaves the control room on Hoth, C3PO can be seen in the background with his hands over his head. The shot changes to a closeup of him, and his hands are now down at his waist.
Continuity mistake: When Yoda and R2-D2 are engaged in a tug-of-war over the little flashlight, Yoda hits him several times with his walking stick. When Artoo lets go, the stick is pointing upwards as Yoda hits him one last time, but in the next shot, Yoda is using it as a walking stick again and it is pointing downwards.
Continuity mistake: When Luke climbs into his snowspeeder, his hair is shorter than when he said goodbye to Han and Chewbacca while on his way to the speeder. When he takes off his pilot helmet on Dagobah, his hair is back to normal. (00:22:20 - 00:25:40)
Continuity mistake: When Leia, Han and Chewbacca follow Lando for refreshments, there is a window beside them. When he opens the door and they see that Darth Vader is there, there is no window but a painted panel with glass bricks.
Continuity mistake: When the Millenium Falcon escapes from the giant space worm, it comes from the center of the mouth, but viewed from outside, it comes from the side.
Revealing mistake: Look carefully at the end of the cavern where the Millenium Falcon enters the giant asteroid. It's a dark blue circle, because the light is dim. But there is a little white circle on the right and the two circles are much brighter on the left side. It's because it's an image of a planet with a moon.
Visible crew/equipment: When the snowspeeders exit the rebel base to go to the battle, there are rails under them.
Audio problem: When Han punches Lando, his hand never makes any contact with Lando's face, and the sound effect is heard after his hand goes past it. (01:29:20)
Continuity mistake: When Luke is hiding behind a corner in Cloud City right before he signals to R2-D2 to keep silent, his blaster is held in different angles between the shot from the back and the shots facing him. (01:35:00)
Revealing mistake: When we see the Star Destroyer for the first time, there are three of them on screen. The one on the top left, can still be seen even after another Star Destroyer came into frame and blocks the view.
Continuity mistake: After Luke is sucked out the window, he grabs hold of two bars in a railing, and his right hand is above the left one. As he hoists himself up in the next shot, it is the other way round: his left hand is above the right hand.
Continuity mistake: Widescreen version: After Vader chokes Captain Needa, he talks to Admiral Piett. The distance between Piett and the officer next to him differs between shots, depending on the camera angle. (01:10:55)
Continuity mistake: After R2-D2 opens the door to the landing platform during the escape from Cloud City, the droid exits through the door. Some shots later, he is back inside. (01:43:55)
Answer: Star Wars being for the young and the young at heart, Han and Leia's relationship unfolds in a deliberately childish manner that kids can relate to and adults will find comedic. Leia is irritated at herself for her attraction to Han, and certainly unamused that Han teases her over it, while at the same time he is not brave enough to admit his own feelings, either.
TonyPH