It looks to me as if "unseen" refers to the UI being "invisible" or "unobtrusive" to the user. One might be tempted to use words loke "obscured" or "obfuscated" if one was less charitable.
Very good ^^. will try to make it "visible" instead of obfuscated. Thank you for your feedback. Minsu (minsu@bbdbu.com, Chief Engineer at buk.io)