Amber Heard 'Gets a Sign' in Derriere-Baring Photo

Amber Heard does not typically share racy Instagram photos, but the actress surprised fans Sunday with a sexy beach photo showing off her derriere.

The 32-year-old Heard posted a photo from her beach vacation, adding "Sometimes you get a sign" in the caption.

Heard did not share the location for her tropical vacation, but she has been posting photos from an exotic locale since last week. She also posted videos to her Instagram story.

While it might look like Heard is not too busy, the actress does have several film projects in the works and is trying to raise money to help Syrian refugee children.

After visiting Jordan with the Syrian American Medical Society, Heard met 12-year-old Weam, and the experience inspired her to launch a fundraiser on GoFundMe's Crowdrise. She has raised $10,845 from 146 donations in 12 days so far.

Heard also became the new global spokeswoman for L'Oreal Paris, joining the likes of Elle Fanning, Julianne Moore and Eva Longoria. She headed to Cannes to attend the brand's Worth It show in May.

"I feel like these woman represent a voice, a power, a movement, an opinion," Heard told PEOPLE last month, just a few days after her dazzling appearance at the MET Gala. "Over the years I've always thought to not just be an actor, but to use my voice as a platform for good to make the world a slightly, slightly better place and empower women the best that I can."

In an interview with the Los Angeles Times, Heard said L'Oreal's "Because you're worth it slogan" took on a new meaning in light of the #MeToo and Time's Up movements. She is also concerned by the gender inequality in the movie business.

"Not only is there workplace inequality in general, ranging from salary to harassment, there's a huge part of this puzzle missing," Heard told the Times. "There are just fewer roles, and even if you were to get one of those roles — some 30 percent of speaking roles — you were still not even considering the content: What are you speaking about? And then we have to apply another filter: Do you have a name? How significant are you to the plot? These are all additional filters by which we can discern how equal the representation of women really is."

Heard will next be seen in Warner Bros.' Aquaman, which opens in December. She also completed the indie movies Her Smell and Gully, which come out next year.

The actress will also be in Hawaii next week for the Maui Film Festival to accept the Shining Star Award. According to Maui Now, the festival runs from June 13 to 17.