What is this warm bright square?

I could here Daila from the other room doing her usual "Ba ba ba" chant while crawling around. She's been doing this lately all day and night testing out every possible octave. Sometimes she gets really excited and kind of shrieks when she does it, and sometimes she almost whispers and does it really slow. It's really cute when she and Kai are laying down sharing a toy together and she whispers it like she's trying to tell him a secret. Well all of the sudden I heard silence and then a constant patting on the floor. So I looked around the corner and this is what I found. This strange new square on the floor pretty much stopped her in her tracks and she sat there and checked it out for a while.