Even if you want to apply judicial ethical standards to city lawmakers, then a member of city council giving a token gift to another member of city council is most analogous to a judge on a panel giving a token gift to another judge on the same panel which... would probably be OK?

Legislators do not sit in personal, unilateral, legally binding judgement of each other, which is why their personal relationships are not analogous to that of a lawyer and a judge as the original article suggested.