This is a CWL layout, so the whole point is freshness. The enemy clan has not seen a replay of it yet, which buys you a few attacks before they learn its gaps. At Town Hall 18 the defence does a lot of the work, and an unseen island base forces attackers to improvise on the first hit.
The tags say what it fears. Anti Electro Dragon means the air defences are spaced so a chain lightning dies before reaching a second, or at most clips something cheap. Anti Air means the seeking mines are where the tanks fly, not where the pets do, and the air defences form a triangle that covers the core. Anti 3 Star means the third star costs more than most attackers are willing to spend, so the base trades clean two stars for stopping the three.
Swap off it once you see it in a friendly challenge or a clan mate replays the same army twice. The island shape is readable, and a practiced attacker will find the one chain that joins two air defences or the funnel that skips the mines. Keep it for a single CWL week if you can, then retire it.
