Applying a mask before bed makes the skin more hydrated.
Tips
usage
敷 (fū) = 'to spread on / apply (a topical)'. Used with substances that sit on the skin: 敷面膜 (face mask), 敷药 (medicated poultice), 敷眼膜 (eye mask). The verb is also the one in 冷敷 (cold compress) and 热敷 (hot compress).