When Luke stepped away from the table, Charlie could see that Luke was wearing a calf-length black skirt. He had also changed shoes and was now wearing a pair of low-heeled ones instead of the loafers he had been wearing earlier. There was enough light that Charlie could see a soft sheen on Luke's ankles. He was obviously wearing nylons.
Seeing Charlie's odd expression, Luke intuited the reason for it, and said, "Well I was making this nice dinner, and I thought would be more appropriate if I didn't come in dressed like Shirley Teen with the short skirt, loafers and Bobby sox!"