While reviewing there's the opportunity to rearrange the page layout. The page/spread must be first put back from 'Review' to 'Design'. And then you can go back to 'Back to Layout'.

Now you can rearrange the layout of the page/spread as you wish. When you are finished you can click 'To Design' and the page/spread generates the Indesign file again with the new layout. Please notice that former Indesign changes of a DTP/Designer outside Relayter are lost!