I took 3 photos but they weren't very good; I found some images of people listening to music instead. I realize this isn't the entire point of the assignment, but I wanted to at least do the analysis part.
1. A man is listening to music but also talking/paying attention to someone else.
This person needs a way to automatically switch contexts between listening to music and someone who is talking, without having to lift the headphones off and/or be interrupted. An mp3 player that automatically detects when someone is speaking and pauses the song, and also amplifies the speaker's voice so it can be heard past the headphones, would be ideal. A "Do Not Disturb" mode that disables this feature would be necessary.
2. This person is running while listening to music.
This person needs a way to run / exercise while controlling her mp3 player. She needs to be able to control the player via verbal commands, and the player should detect her running cadence and supply a song with the appropriate rhythm.
3. This person is taking a nap while listening to music.
This person needs a way to sleep comfortably in any position while listening to music, but simultaneously without bothering anyone else (i.e speakers won't work here). A soft, wraparound set of headphones that enable stomach, side, or back sleeping would be ideal.
4. This group of friends is all listening to music together.
These people need a way to curate a shared music experience. An mp3 player that meets this requirement would have a way of wirelessly connected to a multitude of devices that can queue up songs, as well as either manually connecting or wirelessly streaming the audio to many outputs at once.
5. This baby is listening to music via a device clearly made for an adult. He looks upset.
This little person needs a way to control the mp3 player using only his emotions, since he cannot speak or manipulate buttons. An mp3 player that automatically skips to the next song when it detects crying, and plays the same song on repeat when it detects laughter, would be a great device for this user.
Verplank diagram of case 1: