Those aren't Jump Lists, they are Taskbar thumbnail previews. The Win Explorer Jump List looks like this when multiple windows are open:
When there are too many windows open and consequently too many thumbnails to fit on screen, the list changes to a simple text-based one as shown in the question's screenshot. Windows 7 and later use Application User Model IDs (AppUserModelIDs) to determine which windows to group/combine and which ones to treat separately. It is possible to sort windows within a group, but unfortunately Windows only allows window groups as a whole to be moved on the taskbar. However, a handy utility that provides the missing UI for various taskbar-related options/operations is 7+ Taskbar Tweaker (can be installed in portable mode):
As you can see from the screenshot above, you can either select Drag to reorder under Thumbnails to allow for simple dragging of thumbnail previews, or open the Taskbar Inspector, right-click the relevant window group and select the Sort group items option.