I went through the interview phases, first with HR and then with their Head Designer. They were all really nice and professional, and I liked them a lot. I then completed the tasks I was assigned, which involved quite heavy deliverables. I submitted a fully designed presentation that included concept development, research and analysis, a design prototype, and UX.
Later, I received an email saying they wouldn't move forward with my application, without providing a reason. I followed up by email asking for clarification, and was told they were expecting even more elaboration and graphics.
Considering the amount of design work I delivered, I found this reasoning unreasonable. It made me suspicious that they might be seeking free work during these steps. Additionally, the job posting has been open for about a year, which also makes me think they might not actually be looking for a new hire.