Recent advances in additive manufacturing have made the construction of large-scale 3D-printed structures possible. However, most case studies so far have primarily used concrete as the building material and regular geometries as structural forms. In this work, we present a recently built structural art installation located in Shanghai that is composed of lattice panels with regular and irregular shapes enabled by robotic arm 3D printing. To fabricate the spatial lattice structure, we developed a customized end effector for extrusion-based additive manufacturing using a robotic arm. With the developed printing head and printing path control algorithm, the modular lattice structural panels were printed using ABS material via an industrialized robotic arm and then assembled on the site as a facade. This study showcases the potential to use such modular 3D-printed lattice structures with more freedom in form and partially replace labor with robotic arms for accelerated construction and reduced cost.