Laughing is a mechanic in Bully.
If Jimmy wears unusual clothing, such as his underpants or the cheerful raindeer sweater he gets for Christmas, or even the Orderly Uniform, other students will laugh at him. Although it doesn't make students more aggressive towards him, they won't interact with him normally. Boys will point and laugh instead of allowing Jimmy to hire them, and kissable characters excluding Eunice will laugh at Jimmy rather than accept gifts and kiss him.
All people excluding the authorities and sometimes the tattlers will also laugh if they see someone humiliated, whether by slipping on a banana peel/vomiting, or by being physically bullied.