create table #info
       (
       Date  smalldatetime,
       Brief varchar(20),
       Qty   money
       )

insert into #info
select '2021-09-14 21:36:00', 'Итог за день', 5 union all
select '2021-09-14 15:25:00', 'Товар_3',      2 union all
select '2021-09-14 12:47:00', 'Товар_2',      1 union all
select '2021-09-14 10:22:00', 'Товар_1',      2 

;with cte as 
(select *, lag(qty) over (order by date desc) lgQty  from #info)
select N'За ' + convert(nvarchar, Date, 20), Brief, lgQty - Qty as Delta from cte where lgQty is not null
order by Date desc;