Schematic illustration of the true shape of IRAS 23304+6147. The grid on the right represents the conceptual model consisting of a hypothetical binary star system (filled yellow circles), an EE, and an EDE. The coloration of the grid is defined according to the Doppler effect, i.e., the regions moving away from the observer’s perspective (along the y-axis, as denoted by the arrow below ‘Observation’) are indicated in red, and those moving toward the observer are shown in blue. Four representational velocity slices are shown on the left: a (V_LSR = −3 to 3 km s⁻¹), b (V_LSR = −16 to −5 km s⁻¹), c (V_LSR = −27 to −18 km s⁻¹), and d (V_LSR = −40 to −29 km s⁻¹). The nebula is projected onto the X–Z plane (the sky plane). From the observer’s perspective, from the far to near sides, the EE is first seen in channel a and progresses toward d, while the EDE shifts from channel b to c.