"It's hard to not see your flaws first, [but] I think that, as a society, things are changing. And that's great because every body's being celebrated," Simpson told People in an interview published on Friday, April 15.
The "I Think I'm in Love With You" singer also noted that she's "been every size" so she understands the mentality that comes with different body types. "I understand loving where you're at or wanting more, or wanting something better. I understand that."
The mom-of-three — she shares Maxwell, 9, Ace, 8, and Birdie, 3, with her husband Eric Johnson — explained that she always celebrates her body, no matter the size, because it made her children.
"But you just don't ever think you're going to fit back into things," she added of gaining pregnancy weight. "It's crazy. A woman's body is phenomenal in what it can do."
Simpson also opened up about her recent snapshots shared to social media. "I've definitely embraced myself," she told the outlet, noting she thinks fans and followers understand she's being "open" and "honest" about her life.
"I never thought of being in a bikini again, because I was stretched out as big as the couch," she continued. "So to be able to put on a bikini ... I just hadn't thought that was even a goal until I put it on, and I was like, 'I think I was afraid of that.' "
"It really made me emotional," Simpson confessed, but said she needed to share the photos to remind herself that "the impossible can happen."
"And for me, as a woman, to be able to look as good as I feel was a major moment. You're proud of yourself and you deserve it ... [and you're] understanding yourself and feeling good on the outside," she explained. "When those two things click, the sky's the limit."