@Dazril
Among Lego enthusiasts, certain building techniques are considered “illegal”, typically if they’re highly unconventional, difficult to assemble or disassemble, or place undue strain on the bricks. Here, Blocky Bits is joining two blocks base-to-base using friction pegs, which is considered “illegal” because it places the pegs and holes under constant stress, potentially damaging the parts. Some people take “illegal” techniques more seriously than others - some see it as a challenge to come up with unconventional ways to join parts for fun.