Pusterla, already in close relationship with socialist intellectuals of the caliber of Pompeo Bettini and Gustavo Macchi, showed a decisive orientation towards humanitarian issues starting from 1885. The artist's presence at the First Venice Biennale should be noted with a fundamental work with a social background, Riflessioni dolorose, created between 1894 and 1895, a large canvas with a certain luminous and sentimental effect that captures two sisters, two girls, two small workers as they often saw in that era of hardship and deprivation, one still intent on sewing under the light of a lantern, the other, the younger, stretched out on the work surface, sunk into a child's sleep, her face leaning on his arms, his mouth ajar. A canvas rich in details that emerge from the semi-darkness, from the wicker mannequin that casts shadows with filiform schematism on the back wall, to the ladle and pot hanging next to the window, the room is imbued with a gloomy and heavy atmosphere, enlivened by contrast from the gaudy shapeless chromatism of the red, green and white fabrics, probably to pay homage, as in other paintings of post-unification Italy, to the Tricolor.