Pickering began his career as an illustrator of newspaper advertisements and window display backdrops for Nebraska department stores, such as Quinn's Dry Goods and Ben Simon & Sons. In college, Pickering continued to illustrate, working for multiple student publications at the University of Nebraska. His artwork primarily features people and figures in a comic style, resembling the illustrations popularized in the 1930s by cartoonist and animator Max Fleischer. Most of the clippings in the scrapbooks are in poor condition, especially those for Quinn's Dry Goods.

Pickering retained numerous examples of his artwork. He compiled several scrapbooks of his commissioned work and artwork created for personal use, such as family holiday cards and his own bookplate. Some of his signed illustrations include the postscript “D.D.,” which stands for “During Depression,” indicating that the work was completed during the era of the severe American economic crisis between 1929-1939 known as the Great Depression.

Researchers are advised that some of Pickering’s illustrations contain racist depictions of African Americans, Native Americans, and Middle Eastern individuals. The New School Archives preserves such materials in the interest of understanding the historical context of race relations in the United States. The presence of harmful depictions of individuals and communities in our collections are in no way an endorsement of the racist and oppressive views they represent.