[1] Eisner studied in Germany and worked for the illustrated press from the age of twenty, was trained by Simon Guttmann,[2] head of the very successful Berlin-based agency Dephot (Deutsche Photo Dienst), and her imagery attracted clients including Berlin publisher Martin Hürlimann.

Eisner fled Nazi Germany in 1932 to France where before the War she contributed photography to such journals as Paris Sex-Appeal[4] In 1933 Eisner was Simon Guttmann's representative in Paris, which she continued after the inception, with Fritz Goro, of the agency Anglo-Continental Press-Photo Service in mid 1934, which lasted only a few months, then decided to put her experience in the illustrated press at the service of photographers.

We are trying to organise some kind of association of revolutionary-minded photographers ..."[7]From October 1935,[8] Gerda Taro sold pictures for Alliance Photo[9][10] then started working for the agency as a photographer, and introduced the fictitious American Capa (Endre Friedmann's pseudonym) to Alliance in the hope of higher royalties, but Eisner recognised his imagery and offered him a lower monthly advance of 1,100 francs in return for covering three assignments a week,[7] of which 500 francs were used for expenses.

With the 1,200 francs a month Eisner was paying Gerda, the couple had at last a modest income though they had to work hard; early in April André wrote to his mother that, "In the past four weeks I haven't slept more than five hours a night.

[7] Eisner's particularity was to propose subjects to the editors without waiting for their request and she also promoted her photographers as authors, demanding that their shots be credited in a by-line.

To meet the quotidian interests of the press, it used photographers who recorded current events; Capa, Seymour, Cartier-Bresson and a few others including the Japanese Yōnosuke Natori.

It was Alliance Photo which in 1936 contributed to Vu Capa's famous photograph of a fighter in the Spanish Civil War apparently felled by a bullet.

[14] Images from Alliance Photo were also distributed internationally and published in the United States, Great Britain, Switzerland, Belgium and the Netherlands due to Eisner sales prowess,[15] her fluency in four languages,[16] and her contacts abroad with agencies such as Black Star in New York or ABC-Press in Amsterdam.

[17] Consequently the agency's photographers enjoyed a growing reputation both inside and outside France with Verger, Boucher, Feher and Zuber participating in an exposition Affiche Photo Typo, organised by the Maison de la Culture,[18] and Bellon, Boucher, Feher and Verger being invited by Beaumont Newhall to participate in Photography 1837-1938 at the Museum of Modern Art (MoMA).

[21] In May 1947, Robert Capa organised a meeting over lunch at the Museum of Modern Art in New York with Eisner and LIFE magazine's Bill Vandivert and his wife, Rita, to establish Magnum Photos, Inc.

Whelan records her unease with Capa's anarchic management style, at odds with her own organisation, and his ready borrowing of money from the agency, particularly that of Cartier-Bresson then operating independently in the East.

[24] Capa regarded her impending motherhood as a distraction from her work and delegated George Rodger, briefly returned from Africa, to tell her she was to be dismissed and to arrange her severance pay.