Average Lyα, Si IV, C IV, C III], and Mg II emission line profiles (from left to right) of the images A (black) and B (blue). Blue and red shaded regions indicate the selected windows for magnitude difference calculations, spanning 3000 − 8000 km s⁻¹. We note that the blue wings of Lyα and Si IV are affected by absorption features and have been excluded from our analysis. The observations reveal significant microlensing-induced differences between the images in the red wings of all emission lines. The x-axis is represented on a velocity scale.