In The Final Hours of Portal 2, a screenshot of an early human co-op campaign can be found. In addition, this helped create an in-universe excuse for the constant respawning of co-op players.

In addition, after being changed to a co-op character, play-testers were also reluctant to experiment within the co-op puzzles themselves, due to the consequence of dying without respawning destruction of the co-op bots at the end of each chapter, and the reassembly system for the starting and conclusion of each test chamber, helped tackle this issue. While Mel was still cast as the game's main character, play-testers 'eventually became disappointed' when they found that GLaDOS didn't recognize the player. In the later stages of Portal 2's development cycle, she along with Chell were scrapped from the co-op campaign in favor of the android test subjects Atlas and P-body.

She appears as a blonde haired, blue eyed woman in a light blue jumpsuit with a fairer skin tone than that of Chell. The only valid instance of Mel's physical appearance comes from an early placeholder texture replacement of Chell's model from Portal. Human test subject co-op gameplay by the The Final Hours of Portal 2.

Portal stories mel trailer