Galaxy morphology estimator κ_rot as function of stellar mass for 3824 isolated galaxies from TNG50. Each galaxy is represented with a circle coloured according to the fraction of stellar mass enclosed within 1 kpc of its centre: f_{*, < 1} = M_{*, < 1}/M_*. We indicate the median and the 25th-75th percentiles with a solid black line and shaded region. Filled squares highlight the four example galaxies (A, B, C, and D) shown in Figure 1. Ordered rotation increases monotonically with stellar mass in the 8.0 < log(M_*/M_⊙)≲10.3 range, with dwarf galaxies typically having κ_rot ≲ 0.4. The colour gradient shows that inner regions become more dominant at lower stellar masses, reaching f_{*, < 1} > 0.5, and these galaxies exhibit the lowest rotational support of the sample. At fixed stellar mass, κ_rot is anti-correlated with the stellar-mass fraction in the inner regions f_{*, < 1}.