Personally I think they are an expression of the energy they want to share -art- I don’t have the vocabulary to describe the concept, but that’s as close as I can get.
Particularly the first one, it’s like a burst of energy, like the spring coming, the trees awakening. It’s how I feel when you see the new growth unfurling. Maybe it’s bursting with joy and excitement?

And the second one feels like speed, the lines inside express movement to me, could also be excited or “dancing “

Or like you suggested maybe it’s the movement of the stars or something else we humans are not aware of

This is where I’m used to people saying “yes dear” and politely changing the subject, because they think I’m bonkers

But I hope you understand what I’m attempting to say