Oh I see, that's in the actual paper, not the linked article. Having now re-read that section a few times, I think the important quote is
> The predictive power of the lower face size equaled r(434) = .11; p = .02; 95% CI [.01, .20]. BMI’s predictive power was insignificant r(272) = .06; p = .36; 95% CI [−.06, .18]. Combining the VGGFace2-based predictions (estimated in Study 1) with BMI, lower face size, and with both these variables did not improve prediction performance. The highest performance was afforded by combining VGGFace2 predictions with lower face size. Yet, this model’s performance, r(434) = .21; p < .001; 95% CI [.12, .30], was no higher than the performance of the VGGFace2 predictions alone, r(434) = .22; see Study 1.
> The predictive power of the lower face size equaled r(434) = .11; p = .02; 95% CI [.01, .20]. BMI’s predictive power was insignificant r(272) = .06; p = .36; 95% CI [−.06, .18]. Combining the VGGFace2-based predictions (estimated in Study 1) with BMI, lower face size, and with both these variables did not improve prediction performance. The highest performance was afforded by combining VGGFace2 predictions with lower face size. Yet, this model’s performance, r(434) = .21; p < .001; 95% CI [.12, .30], was no higher than the performance of the VGGFace2 predictions alone, r(434) = .22; see Study 1.