You're reading it wrong.

The section includes income, or loss, depending on the situation. Losses (negative income values) are typically represented with parenthesis.

Income of $25000: 25

Loss of $25000: (25)

Thanks.

They're indicating explicitly that it's parentheses here with the text "INCOME/(LOSS)"

The claim about typicality was to add addition information, not to speculate about this particular case.