Left: Spitzer three-color image of the DR21 complex (IRAC1 is shown in blue, IRAC2 in green, and IRAC4 in red), rendered on the same pixel grid as the column density map in the right panel. Right: Plane-of-sky magnetic field orientation inferred from HAWC+ 214 μm polarization (rotated by 90°), overlaid on the Herschel-derived H₂ column density map of R. Pokhrel et al. (2020) (colorscale). Contours mark H₂ column densities of 1, 2, 3, and 6 × 10²² cm⁻². Pseudo-vectors are spaced by ﹩18\mathop{.}\limits{^{\prime\prime} }2﹩ (4 pixels), approximately matching the ﹩20\mathop{.}\limits{^{\prime\prime} }3﹩ resolution of the smoothed HAWC+ data, which is also illustrated in the lower left corner.