Although Calder often titled his works after he completed them, this work does suggest an abstract homage to a spider—its slender, curved wires, in particular, conjure the legs of an arachnid. Calder has orchestrated a careful balancing act between the large disc and the dramatically cantilevered appendages, which slowly flutter in space with every current of air. A steel rod anchors the sculpture, making this a standing mobile, yet unpredictable movement constantly modifies its form.
The existentialist philosopher Jean–Paul Sartre extolled Calders mobiles. He described the mobile as a "lyrical invention," inhabiting "a half–way station between the servility of a statue and the independence of nature. Each of its evolutions is the inspiration of a split second. One sees the artists main theme, but the mobile embroiders it with a thousand variations."