Though openly gay, Brown is not a gay rights activist and has never used her political position to campaign for gay rights. She does however have a rich history in supporting women's rights - which pre-dates her ANC membership by almost a decade.
Indeed, Brown, 52, has been "out" and in the public eye for many years. So how will her latest appointment change the reality of lesbian women at home or abroad?
What it tells the world
South Africa has previously led the continent on lesbian, gay, bisexual and transgender (LGBT) rights, with a post-apartheid constitution explicitly affirming equality and non-discrimination on the basis of sexuality and gender.
But our record has been tainted more recently, by the government's failure to condemn Uganda's anti-homosexuality bill which includes life imprisonment in some cases.
World leaders lined up in protest, with US President Barack Obama calling it "odious". Meanwhile, Zuma's government issued a statement saying South Africa "takes note of the recent developments" affecting homosexual people and would "be seeking clarification".
A weak response, it did little to budge the world's view that Africa, beset by phobias, lags the rest of the world on gay rights. Indeed, of Africa's 55 states, 38 criminalise homosexuality.
But Zuma's appointment of Brown to his Cabinet - whether or not it had anything to do with her sexuality - has sent a positive message to the world, according to experts.
The Human Rights Watch (HRW) in New York said despite a "regrettable" silence on LBGT affairs abroad, Brown's appointment showed a "willingness to lead by example at home".
HRW's Graeme Reid, director of the LGBT Rights Programme, said that in an ideal world we would "hardly notice" Brown's sexuality, but he argued, it "is significant in contrast to state-sponsored homophobia in many parts of the world".
It tells the international community that a person can reach that level of achievement in South Africa, regardless of their sexuality.
Marianne Møllmann, director of programmes at the International Gay and Lesbian Human Rights Commission (IGLHRC), also based in New York, said: "Symbolically, it gives us something clear to say: Africa is not a monolith."
Closer to home, the appointment proves that South Africa can still play a leading role for the continent. The Coalition for the Advancement of Lesbian Business in Africa (CALiBA) said that the appointment sends "the right message to other African countries and their governments".
What it says about Zuma
Zuma meanwhile is known for his conservative, traditional views. He has long harboured reactionary, homophobic opinions - perhaps most famously commenting in 2006 that same-sex marriages were "a disgrace to the nation and to God".
For Professor Daryl Glaser, head of political studies at Wits University, there is "no evidence that he has changed his personal thinking".
But it's important to note that while Zuma's privately held views might be reactionary, he is "relatively quick to give way to publically sensitive issues", said Glaser.
A recent example is the Traditional Court's Bill, which aimed to centralise power to senior traditional leaders. Zuma eventually backed down in the face of widespread opposition from women's rights groups and other organisations.
"Zuma is not a particularly ideological man," said Glaser. "He doesn't want to make his views an issue”.
Zuma's appointment of Brown can be seen then as testament to South Africa's degree of acceptance rather than exclusion.
Certainly, excluding people from their potential to work penalises not only them, but the country too.
"Exclusion has a cost," Møllmann said, adding: "Countries lose a huge part of economic power then they discriminate."
Preliminary analysis by the World Bank for example, has found that the cost of homophobia in India could reach 1.7% of gross domestic product (GDP).
What it means for the LGBT community
For CALiBA, Zuma's promotion of Brown shows that the South African government has recognised a person for her contribution to the nation regardless of her sexuality.
On this basis, said CALiBA’s executive, it "can be seen as a positive signal to the whole African LGBT community".
Every group needs their role models and representatives, and by being openly gay and successful Brown is showing young lesbians in South Africa that being gay does not have to define your life - or ruin it.
Will Brown go beyond being a role model to become an activist? It is perfectly valid for the LBGT community to hope so, said Møllmann.
"She has an opportunity, she is not in danger - I can see that," she said.
Yet activism is often motivated when someone is personally affected - when someone feels that they have been discriminated against.
It is a deeply personal thing, said Møllmann, adding: "I don't think we can demand that of someone."
Role models aside, her appointment may have little immediate impact on the LBGT community however. For Sheena Magenya, media and communications advisor at the Coalition of African Lesbians (CAL), portraying Brown's appointment as a win for the LBGT community is "a bit careless".
Though her views are personal and not the official line from CAL, Magenya said: "If Minister Brown’s appointment immediately came with legislation that swiftly guaranteed justice for slain, maimed, raped and abused women, lesbians, trans-women, girls and children - then yes, her appointment would be celebrated as a win for the community of poor, queer South Africans to whom this is a daily reality."
What we must do now then is watch what Brown does, said CALiBA. The group said: "We need to watch now all the actions that will be set by Lynne and the conservative government of President Zuma."
It said it expects significant steps from the government, especially in rural areas, to allow lesbian women to live and work according to the protection of the South African constitution.