What did 'Oumuamua see of Earth as it encountered the inner solar system? A speck of light from a distance and, as 'Oumuamua reached its closest approach to earth, perigee (which was at 0.16 au), a disc with dark and bright areas according to the direction of incident sunlight.
Let us ignore the dramatic changes in apparent size and the attached video provides 'Oumuamua's view of Earth if an observer on it had a sufficiently powerful zoom, or a telescope.
Adam Hibberd
June 2022