For the purpose of this debate, brand activism includes campaigns by activists aimed at big brand names to enact specific, measurable policy changes (in their corporate structure) aimed towards sustainability, such as reducing carbon emissions, eliminating single-use plastics, switching to renewable energy sources, etc. Eg. Lush cosmetics actively promoting return programs to aid their pcr (post-consumer recycled) plastic boxes, Unilever's Dove giving up the use of unethically sourced palm oil in their products after being the target of Greenpeace campaigns.
Taxation is centrally imposed by the state onto corporations and can look like carbon tax, plastic bag tax, water abstraction charges, etc.