A Bouncy Stack?

Wobbling toward the sofa corner... three colorful foam drink coasters resting in a neat stack? I paused. Mildly confused... soft rubber biscuits? Safe to touch? Slowly, anchoring my heavy base against the woven fabric, I tilted forward. One careful nudge with my thin limb? Squeak? The spongy foam squeezed flat under my weight, then slowly pushed right back up against my rounded belly! A quiet little lift? I rocked my weight side to side, letting the dense foam wobble with every tiny shift. Soft, springy... safe to stay perched right here?