MacLaine plays a retired businesswoman who loves being in control of everything, while Seyfried stars as a young journalist tasked with writing her obituary.
The two enjoyed their time on set together, saying they shared everything with each other.
"It was a great connection right off the bat," Seyfried said.
Both actresses were also fond of their young co-star Ann'Jewel Lee Dixon, who made her feature film debut.
"She's self-possessed. She, for a very, very, very young human, seems to know what she wants in a lot of ways that I can learn a lot from," Seyfried shared. "She was a light."
According to MacLaine, the film seeks to teach female understanding and promote gender equality.
"For the male audience to understand what females care about, what is it that we sit around and talk about it, what is it that we prioritize," Maclaine said. "That's what it's about for me."