adj. 25B6; adjective
she was unobtrusive and shy : SELF-EFFACING, retiring, unassuming, quiet; shy, bashful, timid, timorous, reserved, withdrawn, introvert(ed), unforthcoming, unassertive.
unobtrusive service : INCONSPICUOUS, unnoticeable, low-key, discreet, circumspect, understated, unostentatious.
extrovert, conspicuous.