A photo of the spouses of world leaders gathered at a NATO meeting in Brussels is getting a lot of attention.

The photo, taken on Thursday, shows Brigitte Macron and Melania Trump, along with a group of women—and one man: Gauthier Destenay.

Destenay is married to Prime Minister Bettel of Luxembourg and is, as Pink News points out, "currently the only national leader in a gay marriage."

AP Photo/Charles Caratini - apimages.com

In addition to reminding people about the lack of LGBT representation in world leadership, it's also a reminder that the overwhelming majority of world leaders are men.

Rex Features via AP Images - apimages.com

It's worth noting that German Chancellor Angela Merkel's husband is not pictured, and British Prime Minister Theresa May left the conference early. Still, as Pew Research Center reported in March, though the number of world women leaders has gone up, "they’re still a small group."

Pew Research - pewresearch.org

"Including Switzerland," Pew reports, "three-fifths of the countries now under female leadership are in Europe."

In addition to being a major problem globally, the lack of female representation is a big problem in United States politics, too. 

Catalyst.org - catalyst.org

As ATTN: reported in May 2016, "there are 435 seats in the House of Representatives. Women hold only 84 of them. And their representation in the Senate isn't much better—there are only 20 women holding seats." (As of May 2017, there are now 83 women in the House and 21 in the Senate.)

So, what's the key to change?

As the World Economic Forum noted in 2015, some of the best countries for female representation are in Africa—and they got the job done by passing laws that established quotas for female elected officials. Rwanda, for example, requires 30 percent of seats be held by women. In South Africa, the number is 50-percent. Bolivia, the second best country in the world for female representation, requires a 50-50 split between male and female elected officials.