Hooper wears a black veil that covers his face almost entirely, and he never takes it off. The effect of the veil is described by one observer as follows:
The black veil, though it covers only our pastor’s face, throws its influence over his whole person, and makes him ghost-like from head to foot.
Therefore, the veil lends a dark and spectral aspect to Hooper, an air of mystery and foreboding, and people are quite scared by it.
However, Hooper’s mouth and chin can still be seen, and this is significant. It hints that behind the obscuring veil he has an ordinary human face, and, moreover, an expression that is downcast and sad rather than threatening. This counters the effect of the veil somewhat.
A sad smile is often observed on Hooper's lips,which would suggest that he is really more of a sorrowful figure than a sinister one. His sorrow is for all humanity, his veil apparently the outward symbol of the sin and misery from which - as he dramatically declares on his deathbed - no human being is free.
Hooper certainly appears as a singular figure, and although he does not really intend it, his strange apparel has the effect of isolating him from the rest of the community. He takes the veil with him to his grave, its mystery never quite dispelled.