I found the Janine scene lovely. I think it was to show the huge contrast to how the babies are raised vs how the should be raised.
Throughout the time in gilead babies are treated as glass ornaments. They're pure and precious and nobody can touch them, there aren't any toys, parks, playgroups or anything to help development or to socialise. Even in the hospital they had gowns, gloves and masks. We don't see them unless they're being married off, and there was the 1 scene when're Putnam had the pram our for 5 minutes. Yes there was the big show off of all the gilead children in series 1 but that was to impress other government officials.
Then the end scene was how it should be done. Laughter, holding, cradling, singing. Touching with skin to skin, interacting with sound and body language and gestures, all of which a baby is born to pay attention too. Janine was in shorts and a vest which is used as underwear but to us (to me anyway) looked just like a normal pyjamas set. It was a sort of flash back scene IYSWIM, of how we all wake up in the morning after a stressful and sleepless night, sit in bed in our pj's and have a quick sing song and play with our children. This would have never happened with Putnam and his wife as we gather from them being sound asleep and very uninterested in their sick child.
The sudden change in baby Charlotte I think was to really really show just how damaging the gilead environment is for children, not just in a sexist, homophobic and religious way but for each development stage too. Their social, emotional and even physical development is continually being damaged and prevented because it's much easier to mould them and brain wash them when they aren't really fully functioning people. And I think this scene will be very important and quite eye opening for aunt Lydia's character.