Both facemasks and makeup tend to result in over-estimation of the young women's age compared to neutral faces, but the combination of both is not additive: 4 years on average

Your ID, please? The effect of Facemasks and Makeup on Perceptions of Age of Young Adult Female Faces. H. Davis, J. Attard-Johnson. Applied Cognitive Psychology, January 28 2022. https://doi.org/10.1002/acp.3923

Abstract: During the COVID-19 pandemic, wearing facemasks was mandatory in the United Kingdom except for individuals with medical exemptions. Facemasks cover the full lower half of the face, however the effect of facemasks on age perception is not yet known. The present study examined whether age estimation accuracy of unfamiliar young adult women is impaired when the target is wearing a facemask. This study also examined whether makeup, which has previously been shown to increase error bias, further impairs age estimation accuracy when paired with a facemask. The findings indicate that both facemasks and makeup tend to result in over-estimation of the young women's age compared to neutral faces, but the combination of both is not additive. Individual level analysis also revealed large individual differences in age estimation accuracy ranging from estimates within 1 year of the target's actual age, and age estimates which deviated by up to 20 years.