It does not make sense. Because, to check whether our subtraction is correct or not, we have to add the difference to the number we subtracted and not the number subtracted from.
The statements may seem confusing and so let us take an example and see. Say we have 25 and 5 and we are subtracting 5 from 25.
We have 25 - 5 = 20.
Here, the difference is 20, the number we subtracted is 5, and the number we subtracted from is 25.
As per Nina's statement, if we add the difference (20) to the number we subtracted from (25), we get 45 which was nowhere to be seen before!
On the other hand, if we add the difference (20) to the number we subtracted (5), we get 25, which is the number we subtracted from.
Hope it is clear now!