chapter6.3 bidirectionRNN about yield samples[:, ::-1, :], targets

as the book says **_yield samples[:, ::-1, :], targets_**. why the **_targets_** does not change as _**targets[::-1]**_, I get it,sample.shape is (128,120,14),five days record time point 120,reverse read 120 time piont datas makes no diffrences to the targerts.