Continuing with the "First and Last" series of shots:
The first and last shots we see of the twins are interesting.
Leia has always "had her eyes open". She is a confident woman, but uses her position to secretly influence the fate of the galaxy.
She is "safely anonymous", but at the start of ANH, she lowers her hood, as her anonymity comes to an end and she is captured by the forces of evil.
Luke on the other hand was born with his eyes closed to his influence and destiny.
In ANH, with the arrival of 2 droids sent from his sister, he slowly awakens to the truth of his lineage.
The Wizard:
Here we see the entrance and exit of Obi-Wan. Described as a crazy, old wizard never has he appeared more wizard-like with his Jedi hood raised forming the impression of a wizard's hat.
This is of course fitting as Kenobi is the Gandalf character in the OT, a spiritual mentor who can transcend death to give guidance. Kenobi is seen as a shadowy visage.
Note, the same as Vader, when the Saga is watched 4-6,1-3 we first see Kenobi walking towards the screen and last see him walking away. As if he has been given a proper entrance and exit to viewers.
Also the first and last time we see him, he is leaving then finding Luke.
AN ELEGANT WEAPON:
Another visual bridge, almost left out in error by Lucas, the first and last lightsaber we see on screen is the same - that belonging to Anakin Skywalker/Darth Vader.
A symbol of the title of hero of the Saga being passed from father to son, through their joint mentor Obi-Wan.
Related to this - the first and last lightsaber we see in action is also the same - it is that of Kenobi's.
The situations however could not be more different.
The first lightsaber slash we see incapacitates a nothing villain, just a bully who taunts Luke in the cantina.
The last lightsaber slash we see is arguably the most important in galactic history as it incapicitates the Chosen One of Jedi/Sith legend - limiting the power of Darth Vader with the Force:
Also, C-3PO has the first and last speaking lines of the trilogies:
"Did you hear that?"-ANH
"Oh no!"-ROTS
But to quote Doctor Emett Brown: "on the other hand, this could all be an amazing coincidence. 😛
TECNOLOGICAL TERROR:
The Death Star, making its first appearance as a real object in the Saga, is viewed as a small, incomplete object from the bridge of a massive Star Destroyer.
Contrast this to one film later as we see the true scope of its construction - dwarfing a Star Destroyer, complete in all its glory.
An interesting point to note is also due to the ingenious order the ending montage of ROTS plays out with we see the Death Star followed immediately by our only glimpse of Alderaan. The planet which will of course be destroyed by it 19 years later.
The same montage shows us Padme's funeral - iris on pendant given to her by Anakin - to Anakin, now as Vader, overseeing the Death Star construction - iris out to Alderaan, the planet it is tested on - iris out on Leia's open eyes to her brother Luke, with closed eyes being delivered to the Lars' homestead.
And just for fun:
GUARDED ENTRANCES
Vader enters the Seperatist den, flanked by Trade Federation guards. Nobody opposes him, and nobody will last very long in Vader's slaughter.
Yoda enters Palpatine's den, initually opposed by the Red Guards. They don't last long, though, as Yoda takes them out quickly with the Force.
Luke enters Jabba's den, initially opposed by Gammoran guards. They don't last long, though, as Luke chokes them with the Force. It's also worth pointing out, as others have, how Luke's Jedi violence on the Sail Barge mirrors Vader's Sith violence on Mustafar.
Right then, here we are.
"THROWING A WEAPON AWAY"
"So uncivilized," says Obi-Wan Kenobi, disdainfully tossing away the blaster he used to vanquish the cyborg warrior, General Grevious.
"I'll never turn to the dark side," says Luke Skywalker, defiantly tossing away his lightsaber, refusing to slay his bested father, the cyborg Sith Lord, Darth Vader.
Besides the obvious comparison point, here's a short bit of commentary-- Obi-Wan tosses to the left, and Luke to the right, another parallel/inversive variation on a repetition. Obi-Wan tosses away his blaster not because it's a weapon, but because it isn't a Jedi weapon, still bearing a rather aristocratic lack of respect for anything other than a lightsaber. By the end of ROTJ, though, Luke has surpassed the vision of his master, realizing the futility of all violence and the moral coruption of all weapons. His lightsaber may be a more elegant weapon of a more civilized age meant mostly for defence, but it is still, as Hatori Hanzo says, "something that kills people." Throwing it away is a sign of Luke's acceptance of pacifism-- and its possible conequences at the hands of the powers-that-be-- and a testament to his mastery of the Force. Only when he is weaponless does he truly become a Jedi.
ANAKIN AS A JEDI:
The only two occasions we see Anakin dressed as a traditional Jedi in the Saga are just after his induction into the Jedi Order and then just after his rebirth as a Jedi.
The shots form bookends to the Saga, and Kenobi casts a watchful eye over his new/former apprentice on both occasions.