What does serving face mean?

serving face means: A pose for a photograph, often with an unaffected, serious look. The “smize” is similar. “. (in Community Dictionary, added by Makena Barron)

What else does serving face mean?

• Photographing yourself intensely. Particularly, working on your face. Drag queens often use this phrase. (in Community Dictionary, added by Petronila Serrano)