Turning head side-to-side with mouth open?

Silver • 👶🏻9/23👶🏻4/22👶🏻12/19❤️👩🏻‍🤝‍👨🏼🐕🐕

Anyone else’s baby do this? If so, what does that mean for your baby?

My son started doing this maybe 1-2 weeks ago (he’s 6 months) and it kinda looks like he’s hungry and searching for bottle/boob. But then when we give it to him, he’s not actually interested? Could he be indicating he’s interested in more solids? He’s not usually sleepy when he does it, so I don’t think he’s tired.