I heard it was hard to get into so I applied for fun, mostly. I didn't even have designs to show them because I never designed a t-shirt in my life, and I got in. All I did was say I had success with other t-shirt design websites and would like to expand, and was accepted the next day. My account might be deleted now due to inactivity since I never did anything with it.
There may be luck involved because I've seen a lot of people complain about rejections and my one off experience is probably not the norm, but my application was probably three or four lines of text. I just told them what I thought they wanted to hear from someone applying—that I had experience and was already successful.
Even though my experience was probably a fluke, maybe you should try my method of keeping it short and sweet if you're putting a lot of work into the application.
Who the hell knows? They might choose people randomly, or maybe whoever accepted my application appreciated the fact I kept it short after reading walls of text about how people got started in t-shirt designing.
Anyways, good luck. Hopefully someone else can chime in with more advice.
