How to reorder the assets in an album in the Pro interface.
Sorting the assets in an album
To sort the assets in an album, first drag the album from the right side panel to the tab area above the grid to create a new tab for it. To be able to drag the album, click on the corrugated left bar in the album and drag.
With the Grid view active (press G if it's not already enabled) you can now select assets in the album and use the C and V keys on the keyboard to move the selected assets to the left (C) and right (V). If you select several assets that are not placed next to each other, pressing either C or V will group them.
To move the selection to the beginning or the end of the archive, use Shift-C and Shift-V.