When you beat the game, at the end of the ending sequences, you will see a portrait of Samus. There are five possible portraits, depending on how many upgrades you collected and how long it took you to win the game.

The Endings

Time: 4+ hours
Items: less than 100%
Samus: In full Fusion Suit, hand on hip.

Time: 2-4 hours
Items: less than 100%
Samus: Back turned, in Fusion Suit with helmet removed, with a bright star in the background.

Time: Under 2 hours
Items: less than 100%
Samus: Leaning back, Fusion Suit removed.

Time: 2+ hours
Items: 100%
Samus: Fusion Suit removed, in front of a city skyline.

Time: Under 2 hours
Items: 100%
Samus: Fusion Suit removed, hand on hip.