With the advent of the digital age, technology has empowered the interactive potential inherent in digital public art. Digital public art breaks the traditional aesthetic contemplation of public art, blurring the boundaries of the aesthetic subject-object duality. The artistic effect it presents allows the aesthetic subject to demonstrate initiative, participation, and interactivity, aligning with the concept of "theatricality" directed towards the audience. Derived from the field of drama, "theatricality" refers to the relationship between the audience and the performance, emphasizing the projection, interactivity, and level of audience participation in the artwork. This resonates with the perspective of the aesthetic subject participating in the aesthetic object in digital public art. This paper attempts to explore the theoretical roots behind the interactivity of viewers in digital public art and combine it with the theory of "theatricality" to understand the representational tendency of digital public art. Based on the theory of "interstitial" dialogue, optimizing Abrams' "four elements" theoretical framework, constructing an internal semantic paradigm with "audience" as the core, in order to explain the aesthetic significance generation mechanism of the "theatricality" of digital public art.