Good question @andrejcibik. We look primarily at the logo itself and not necessarily the premise of the blockchain behind it. An example, Bitcoin was the first logo challenge. But we skipped Bitcoin Cash because there was too much similarity (visually).
This challenge is about using Steem as a forum for exploring all crypto communities. We hope and encourage other blockchains to take the Steem community seriously as a crypto-fluent audience (that they should want to build a presence upon) and one that is exceptionally creative.