Mandy Moore On Sharing 1st Holiday Season With Baby Gus, Making Her 'This Is Us' Directorial Debut (Exclusive)

The actress spoke to ET ahead of the premiere for season 6 of 'This Is Us.'

Mandy Moore is looking forward to the holidays with her family. The 37-year-old actress is getting ready to celebrate the season with her baby boy for the first time.

Moore walked the red carpet at the premiere of the sixth and final season of This Is Us, held at Paramount Pictures Studios in Los Angeles on Tuesday, and she spoke with ET's Denny Directo about her and husband Taylor Goldsmith's 9-month-old son, Gus.

According to Moore, becoming a parent has opened her eyes to the true meaning of this festive time of year.

"I understand now, yes, the significance of the holidays," she shared with a beaming smile. "I'm very, very excited to have our first holiday season together."

Moore and Goldsmith welcomed baby August on Feb. 20, and she recalled how he was very young when she was already taking him to the This Is Us set.

"He's come to work with me since he was like a month old," Moore recalled. "So he's seen me in different makeup and wigs and everything."

Moore said he often stares at her when she's wearing makeup to play an elderly version of her character in the show, with a look that seems to imply he's thinking, "You have the same voice, you smell like my mom, but you look like you're 70.'"

"I know it's a little confusing, probably," Moore said, joking that he'll either have a fun time looking back at pictures of his time on set with his mom in elderly prosthetics, "or [need] therapy."

While season 6 is set to premiere next month, the cast and crew are still hard at work filming the final episodes of the series. In fact, Moore is actually helming the episode currently in production in what will mark her directorial debut.

"It's such a dream," Moore marveled. "The episode is so good."

According to Moore, the episode she's directing is largely focused on Chrissy Metz' character, Kate Pearson, who is the daughter of Moore's Rebecca Pearson.

"The fact that I get to do her episode, and the final telling of a very important chapter in her life, [it's great]," Moore shared. "There's such a difference between sitting behind a monitor and watching a monitor, versus being in a scene with someone. I've been working with Chrissy for six years now, and I was watching her on a monitor doing a scene the other day and I was just [wowed.] It blows my mind how good these friends of mine are at what they do. I have a whole new appreciation."

In fact, Moore said that the comfort and familiarity her co-stars have with their characters, and their level of undeniable talent, makes directing them feel almost effortless.

"I don't have to do anything, honestly, with this crew," she said. "I just sit there and go, 'Just do your thing!' It's amazing."

Season 6 of This Is Us debuts Jan. 4 on NBC.