Nessim received encouragement from her former teacher, Robert Weaver, to enter the Society of Illustrators 2nd annual competition in 1960 where she was awarded a Special Mention for a series of seven innovative monotype etchings titled, Man and Machine.

Nessim was immediately noticed by leading Art Directors of the day, notably Henry Wolf and Robert Benton from Esquire Magazine.

Nessim was one of very few full-time professional women illustrators working in the United States during the 1960s;[2] she was able to carve a niche for her work in the competitive graphic design field, illustrating record album covers, calendars, and magazine covers for major publications such as Rolling Stone, Time, Ms, New York Magazine, The Boston Globe, Show and Audience.

[1] She established her own graphic design firm in 1980, Nessim and Associates, with a group of fellow illustrators to work on corporate projects.

[3] Nessim produced many works in ink and watercolor, and later incorporating computer graphics into her arsenal of mediums she mastered.

In 1980 she was invited to participate in the Massachusetts Institute of Technology's Visible Language Workshop (VLW), a program designed to carry out experiments for advanced graphics research.

In 2009 Nessim launched The Model Project, a “cutting edge view of fashion’s hold on women” expressed in a series of large scale collages printed digitally on aluminum panels.

Nessim deconstructed the images, “juxtaposing cutouts of lips, hair, breasts and legs with jewelry and clothes to re-examine prevailing ideas about desire, beauty, fashion and commerce.”[7] Nessim’s permanent installation, Chronicles of Beauty (an extension of The Model Project) was commissioned for New York City’s Eventi Hotel.

It would all depend on the approach I wanted to take for each artwork I was doing.”[8] She acknowledged the difficulties illustrators have faced in adapting to the technology in a 2003 interview: “it is challenging to be constantly learning something new all the time.