Compared are the shortened "Bob Dole" Version and the longer MTV Version of Britney Spears' first of two huge Pepsi commercials that are almost a video clip.
The biggest difference are the added comedy ssenes and the three cuts in the Bob Dole Version.

The time index marked with "*" refers to the MTV Version.
Running time MTV Version: 2:00 min
Running time Bob Dole Version: 1:30 min

Different scenes: 11
Song cuts: 3

0:21 sec (0:23 sec)*
Different scene

MTV Version: Britney's dance performance continues.

Bob Dole Version: Two shots of a cook. The first one from behind, he's watching dancing Britney on TV (what's in the MTV Version). And another one from the front side, there's a fire behind him in the kitchen.
5 sec = no difference

0:24 sec
Shortened song during the shot from the front side in the Bob Dole Version. After the line "Everythings alright...", the song actually continues with one of Britney's dance performances.
The cut has been covered up by the scene with the cook and doesn't catch the eye.
10 sec

0:34 sec (0:46 sec)*
Different scene

MTV Version: Extended shot of Britney and her dancers. CUT to Britney who's standing behind a conveyor with Pepsi cans on it.

Bob Dole Version: Britney moves her arm from the left to the right. CUT to five women in an bowling alley - one of them copies Britney's movements.
1.5 sec = no difference

0:36.5 sec (0:48.5 sec)*
Same frames of Britney behind the conveyor have been added here.

The MTV Version contains an extended slow motion shot of Britney and her dancers.

0:44.5 sec (0:56.5 sec)*
Different scene

MTV Version: Britney's face.

Bob Dole Version: Two Pepsi cans collide.
0.5 sec = no difference

0:52.5 sec (1:04.5 min)*
Different scene

MTV Version: Extended shot of a dancer taking a pull on a pepsi can.

Bob Dole Version: Pepsi cans are falling from the sky.

0:54.5 sec (1:06.5 min)*
Different scene

MTV Version: Distance shot of Britney leaping up into the air.

Bob Dole Version: Britney in front of a Pepsi logo.
0.5 sec = no difference

0:55.5 sec (1:07.5 min)*
Different scene

MTV Version: Different shots of Britney - two Pepsi can enter the scenery in the meantime.

Bob Dole Version: Three different shots. The first one shows hospital staff swaying to the music in front of the TV. The second shows the same with a guy in a dark hangar. The third one shows the cook again. This time, a fireman is in the background and kills the fire - the cook is still standing there. He seems mesmerized or sth.
4 sec = no difference

1:00 min (1:12 min)*
Another shortened song. Shots of Britney in front of the logo, the Pepsi cans, the dancers etc.
10 sec

1:06 min (1:28 min)*
Different scene

MTV Version: Lots of shots of Britney. In front of the logo, dancing with the other dancers - cut pretty fast with many many shots and angles.

Bob Dole Version: First a profile shot of Britney while she's drinking Pepsi (parts of it are also in the Bob Dole Version). CUT to the cook. He's still mesmerized in front of the TV and doesn't even notice the fireman waving his hands around in front of his face. CUT to to a Coke booth. The workers are moving to the music in two different shots. CUT to the retirement home. An old guy passes an oxygen mask to another one who puts it on.

1:19 min (1:41 min)*
Different scene

MTV Version: Extended shot of Britney and the dancers. They're dancing in front of the Pepsi logo.

Bob Dole Version: Shot of an elderly guy on the couch with a Pepsi can in his hand. The dog next to him howls.
1 sec = no difference

1:21 min (1:42 min)*
Now the last cut scene: many shots of Britney, her dancers,, the crew etc. are missing. These scene sound the bell for the end of the video.
10 sec

1:25 min (1:56 min)*
Different scene

MTV Version: "The Joy of Pepsi" logo, then Britney applauding with a can her hand.

Bob Dole Version: Shot of an elderly guy with Pepsi can in his hand. He tells the dog "Easy boy" after he (the dog) barked. Subsequently, Britney applaudes. Then the "The Joy of Pepsi" logo. The last scenes are shorter which is why both versions have the same length here.

5 sec = no difference