The present research investigates the appreciation of sanctioned street-based art among naïve viewers. It examines the role of viewing context in art appreciation, by experimentally testing a gray cube effect, which posits that street-based artworks are more likely to be identified as art (H1), liked more (H2), and understood more (H3) when viewed on the street. Identical procedures were carried out in Hong Kong (Experiment 1) and Lublin, Poland (Experiment 2), separately, sampling local artworks and local viewers. Experiment 1 tested 14 murals with 100 Hong Kongers; Experiment 2 tested 7 sculptures and 7 murals with 88 Poles. Participants were randomly assigned to either viewing street-based artworks on the street (gray cube) or viewing digital images of street-based artworks in a laboratory. The participants assessed each artwork in terms of art identification, liking, and understanding. These “twin” experiments yielded identical results, i.e., street-based artworks were liked more (H2) and understood more (H3) but not more likely to be identified as art (H1) on the street than in the laboratory. Overall, the present findings support the gray cube effect with ecologically valid data, and the effect seems robust across Western and Eastern cultural contexts and across genres of sculpture and mural.