There are a lot of numbers, and they aren't given in a way that makes the important ones prominent and the parallelism between the two framings transparent. You're switching between a $500 increment and a $1,000 increment, varying the number of children between 0, 1, and 2, and repeating the $35k and $100k numbers (which are distracting labels for the groups, not relevant numbers). Was the setup:

Option 1

• rich 2-child pays $26,000
• rich 0-child pays $27,000
• poor 2-child pays $3,000
• poor 0-child pays $4,000

Option 2

• rich 2-child pays $25,000
• rich 0-child pays $27,000
• poor 2-child pays $3,000
• poor 0-child pays $4,000

with Option 1 preferred when it's a tax reduction (0-child is the baseline) and Option 2 preferred when it's a tax penalty (2-child is the baseline)?

I might get rid of the numbers entirely, and just say something like: Another study explored the idea that families with more children should pay less in taxes, framing the tax difference as either a reduction or a penalty, and tested whether people thought the amount of the reduction/penalty should vary depending on the family's income. In one version, two-child families pay less than families without children because of a tax reduction, and in the other families without children pay more than two-child families because of a tax penalty. Of course, the two versions are equivalent, but when it was framed as a tax penalty most people wanted the size of the penalty to increase as the family's income increased, but when it was framed as a tax reduction most wanted the size of the reduction to be the same regardless of the family's income.

Maybe you could add a sentence or two at the end with the relevant numbers.