App Partner User Experience Designer interview questions

Very strange. I've never experienced an interview like this before. They said sent an automated message that asked me to complete about 6 hours worth of a design challenge to design an app. This is without an initial phone call or explanation. Then when I got on a short call with the HR person (I assume), she had no further insight into the position than what was on the application. Also I mentioned that if I'm spending 6 hours of my time making this presentation, I should at least be able to come in and describe my thought process and decisions. She said there are too many people and applications to look through, so I wouldn't be able to do that. She said there were at least 15 they gave this prompt to and growing. The call ended when she mentioned that the cap for a mid-level designer was $60k. This is insane.