university prof can get away with mroe than high school teachers can aloud to swear etc but involvment with student is something they may lose a job over so I doubt any would risk all the work they put in. I would just take it at face value as a compliment and nothing more unless it starts to become a constant problem then I may worry.
thats kind of a normal thing to do. even if your not into someone, its sometimes just nice to say "u look good!" or "have you lost weight?" its a good ice breaker, because its a compliment and it gets a convo going.