look (one) up and down
To visually inspect one in a blatant and often tactless manner. When I stepped into the office, the boss looked me up and down before telling me to take a seat. I looked the strange woman up and down, wondering if she were really here to help me or just another spy.
look somebody ˌup and ˈdown
(informal) openly look at somebody from head to foot in a way that makes them feel embarrassed: When I started working there, I could feel people looking me up and down and wondering what I was like.