Visible crew/equipment: When Andy talks about naming the baby "Bernardo", a boom mic can be seen reflected in the glass of a cabinet to his right.
Visible crew/equipment: When Nancy gives the story about being aware of her people there's a flashback to when she's at the space exhibit with Stevie. If you look to the right of the screen when she's hugging him, you can see the shadow of the boom operator's microphone being held above their heads on the back curtain behind Stevie and Nancy. (00:27:20)
Answer: It's not uncommon for TV shows to suddenly "age up" baby/toddler characters in order for them to have more narrative purpose. Other examples of shows I can think of that did this are "Step by Step," "Last Man Standing," "Boy Meets World," and possibly "Dexter."
Phaneron