Krishna offers one of the Gita's most vivid images. Just as a necklace holds many pearls, all strung on a single thread, so this entire creation is strung upon Me. The thread is invisible. You see the pearls — the sun, the moon, the trees, the rivers, the people — but not the thread that holds them all together. Remove that thread, and the pearls scatter.
When a grandmother strings a mala, the first thing she picks up is the thread. Without it, the beads are just a pile. That thread, unseen but holding everything in place, is what Krishna calls Himself. He is the invisible force connecting all of existence.
The first half of the shloka is equally direct: nothing whatsoever exists that is higher than Me. No power, no principle, no entity stands above the divine. This is a clear, unambiguous declaration of the supreme nature of the Lord.