Comparison of rest-UV (F150W) and rest-optical (F277W) effective radii for protocluster (red squares) and field (blue circles) LAEs with valid size measurements in both bands. The dashed line indicates the 1:1 relation; galaxies below the line have more compact UV emission relative to their optical extent (R_e,UV < R_e,opt). Field LAEs are broadly consistent with the 1:1 relation within their scatter. Protocluster LAEs tend to lie below the 1:1 line, but this difference is not statistically significant. This is consistent with the rest-optical size enhancement identified in Figures 2–3.