She was associated with a group of artists from Kraków (the so-called Kraków Group) and Warsaw; and she exhibited her works at the Krzysztofory and the Krzywe Koło galleries. Yet, she largely identified with the circle of Tadeusz Kantor, especially with the tradition of surrealism recreated in an intense and varied manner by this group. She also took part in meetings of experimental artists, mainly the Złote Grono Symposia (Zielona Góra 1963, 1977) and Plenery Koszalińskie (Osieki 1964-67, 1972, 1976-78).
Erna Rosenstein studied at the Frauen Academy in Vienna from 1932 to 34 and the Academy of Fine Arts in Kraków between 1934 and 1936 (under the direction of Wojciech Weiss). As a student, her leftist views drew her close to the Kraków Group. She got on well with Jonasz Stern, among others (Stern and Maziarska, 1946). After Stern’s death she talked openly and warmly about his dramatic life, personality and creativity. In 1937 Rosenstein took a short trip to Paris. She spent the war with her parents in Lviv. In 1942, she managed to escape from the ghetto there. She survived the occupation by hiding under different surnames. An expression of those experiences is the painting Ghetto (1946), referring to the myth of Niobe. The plasticity of the figures and the powerful expressiveness make this work comparable to the equally dramatic composition of the same name – Ghetto by Izaak Celnikier.
After the liberation Rosenstein joined the Group of Young Artists, which took up the artistic activity of the pre-war Kraków Group. When the latter was reactivated in 1957, she naturally became a member, although she'd lived in Warsaw since 1949. She took part in the Exhibitions of Contemporary Art (1948-49 in Kraków, 1957 and 1959 in Warsaw), as well as in the historical exhibition Nine (1955), along with Tadeusz Brzozowski, Maria Jarema, Kantor, Jadwiga Maziarska, Kazimierz Mikulski, Jerzy Nowosielski, Jerzy Skarżyński, and Stern.
Her earliest works were figurative, with the human figures being firmly structured, coherent, robust, sculpturally modelled as a lump of clay (as the above-mentioned Ghetto), or divided into hieroglyphs created by free brush strokes (Stern and Maziarska).
In general, however, Rosenstein’s painting and poetry constitute an individual ‘travesty’ of the surrealist experience, though the artist said she did not like to be called a surrealist. Her works have been said to resemble eastern miniatures or old, Asian charms (Heraldic Animal Kingdom, Magical Board from around 1955). One critic said that: ‘[...] Her painting is extremely warm, decorative and far from sophisticated syntheses, but full of fairytale symbolism’ (Andrzej Łepkowski).
Rosenstein consistently adhered to these kinds of poetics for decades. She was fond of strange and in many ways surprising combinations, in which she mixed elements from different worlds and orders: the real and the unreal, the sensual and the spiritual, the tangible and the elusive. She dissolved boundaries: between the serious and the frivolous, the mature and the immature, the cultivated and the naive. She merged reality and fantasy freely, without being burdened by a scheme. Rosenstein used both recognisable forms (portraits of loved ones, including Alan Kosko and Artur Sandauer) and completely abstract ones (Silence Burns, 1996). She arranged the latter in hieroglyphic subtitles (Where Did It Come From, 1985). She also sometimes changed her artistic strategy unexpectedly and emphasised the structure (for example, the texture) of a painting instead of its meaning (Anniversary, 1991). This kind of ‘Tower of Babel’ of forms that she used constitutes a uniform, though fragile construction. Most of the elements are linked by a hardly perceptible meaning, which is the result of the artist’s desire to get as close as possible to what is personal in a visual and artistic way. Indeed, Rosenstein invites the viewer (and the reader) on a journey in the world of personal experience and memories, originating from intimate fantasies and dreams. In this world there is either acute tension, or lyrical mood of gentle sadness, nostalgia, memories, and endless revolving dreams (Source, 1965; Horoscope, 1964).
Rosenstein is characterised by the desire to ‘break free from associations or abstract expressions of her aspirations and longings, presented as honestly and clearly as possible, beyond the help and security provided by conventions’, wrote Maciej Gutowski. She does that in many ways. Initially, she draws attention to the pictorial space, which is highlighted by lively overlapping forms and diffused colour stains, sometimes making reference to objects, and often not. In many compositions an essential function is fulfilled by the precise contour, as well as ‘[...] the line swirling in fast motion. The line, which becomes a record, an automatic action; the line, which, as in a signature, takes, because it must take, its unique and only course’ (Maciej Gutowski). With time, the artist started focusing almost exclusively on creating a lyrical aura, which determined the nature of the paintings. Her drawings (mostly made in black ink on white paper) have a similar atmosphere and appear to be much richer than the paintings on a purely aesthetic level. The diversity of spaces, perspectives, lines, lights and shadows, as well as shapes, themes, and allusions is simply unlimited.
Initially, the 50s and 60s were dominated by organic forms. It is easy to sense that the artist was fascinated by the vitality of nature, by its unrestrained transformation into new forms. Rosenstein’s drawings from that time were marked by horror vacui and were tightly filled with a variety of elements (Different Head, Same Head, 1955; Witches’ Sabbath, 1968).
Her 70s compositions were more structured. Rosenstein used geometrical and sometimes architectural forms (Very Heavy Sky, 1976). By contrast, in the early 80s she could sometimes leave a piece of paper almost empty – with only a few expressive strokes (In the Wilderness, Signposts, both from 1980). This somewhat alchemical attitude of constant search characterises all her art.