Is there anything other than a mobile thats safe for crib?

In baby’s bassinet theres a stitched in, crinkly fabric, black and white text label that oddly baby loves because of the noise and colors I think. She will self soothe for several minutes while “playing”. But she’s almost totally outgrown it.

It makes me feel like she wants something in the crib while she falls asleep.

What, if anything, is safe to add?

A friend suggested maybe medium stickers on the crib slats that are taped on.

Wondering other things I can use.

She’s only in crib for overnight sleep. But would also like to use it for those 15 minute showers, or sweeping etc. but she needs stimulation.

TIA