"Insightful, we said. Professional, we said..."
In the footage, stars including Renee Bailey and Stephen McGann can be seen having sing-song, while the cast can also be seen celebrating Megan Cusack's birthday.
Other shots see Cliff Parisi complaining about filming from different angles until it leaves him "spinning around in a mad perpetual circle", and Natalie Quarry is seen dancing through the corridors.
You can watch the footage right here now:
Fans don't yet know much about what's in store for their favourites in this year's Christmas special and the 14th season, but McGann previously teased a mix of "fun" and "darkness" in the festive instalment.
Read more:
Speaking with RadioTimes.com alongside Rebecca Gethings on the NTAs red carpet, McGann said: "It is all the fun of the fair, and also the normal kind of darkness you would expect with Call the Midwife."
Gethings teased: "There will be tears and laughter, it's heartwarming as always. It's about community, but yeah, they're always tested at Christmas, it's not just about cuddles and Horlicks."
By entering your details, you are agreeing to our terms and conditions and privacy policy. You can unsubscribe at any time.
McGann added: "And it's a very special episode, Christmas, for us in our show, and that's the one people particularly respond to.
"I think it comes in as part of the festival and the year, which we're incredibly flattered by, but it makes it that bit more special. Christmas is a special one."
Call the Midwife will return to BBC One at Christmas. Previous seasons are available to stream on BBC iPlayer.
Check out more of our Drama coverage or visit our TV Guide and Streaming Guide to find out what's on. For more from the biggest stars in TV, listen to The Radio Times Podcast.
