Apparently IU looks like... well, herself!
She showed her travels in Taiwan through her 'IU TV'. She was going around the night markets of Taiwan when a Korean tourist told her while passing by, "You look like IU." IU was surprised by the comment and told the camera, "That was Korean! They said I looked like IU."
The staff jokingly asked IU, "Do you hear that often?", to which she responded, "Sometimes." They also asked, "What do you think about IU?," and she joked again, "I don't think she's bad."