Because the accountant for the estate sent a supporting document that states that these are deductions due to Loss Carryovers. The IRS form is not just meant to be for reporting income. Right above where you have highlighted IRS heading is "Beneficiary's Share of Current Year Income, Deductions, Credits and Other Items". So although the box titles say Income, Dividends, etc. The form can be used to report Deductions in those categories. Those are losses suffered by the estate. Typically when that is done, accountant provides a supplemental document that clarifies that the amounts are deductions and not income.
