Playing With Her Tongue - Anyone Else?

Kristen • Hubby & I have been together 10 years, married 11/8/14. Angel Baby - 10/22/15. Rainbow Baby Girl, Maggie, born 10-18-16!
My 4, almost 5, month old has been playing with her tongue a lot the last few days. It's hard to describe since we can post videos....But I screenshotted it as best as I could. She like stick it out of her mouth, real flat, and then like tucks it between her lip & bottom gum. Any other babies doing this?
(She's still only bottle fed break milk, no solids yet.)