It means that increasing salaries that are too low can reduce job dissatisfaction, but increasing salaries that are already generous won’t increase job satisfaction in any meaningful or lasting way.
Once the museum field “reduces dissatisfaction” in jobs by equitable and transparency around pay, the next step would be to look at how the field could offer moving between roles as a motivators for job satisfaction. How amazing would it be to evaluate museum jobs based on what you will learn from other members and/or as your role evolves within the organization?