The graphic displays and reporting for sleep tracking were revised in the latest app update -- version 4.20 on iOS. The new layout is a significant step backyard in terms of user experience.
The biggest loss of valuable information and utility is in the 7 day view. Previously, it displayed each day on a horizontal bar, color coded to type of sleep, and plotted precisely to time. So one could see how consistent or inconsistent their overall sleep timing was, start and finish, as well as how their sleep cycles compared over the seven days, again, including tied to specific time. With the new revisions, this information has been reduced with the new vertical columns that only show cumulative time per night in any given part of the sleep cycle --- significantly less information than previously, and not nearly as meaningful. This is a significant step back in user experience and I strongly encourage you to restore or rework the layout to include the previous information and value.
Secondarily, meaningful information is also more difficult to find having to scroll down to the time graph, rather than being on the main screen, and with the info on stages occupying an unnecessary amount of space. Even worse is the loss of utility with the new "Movement" graph, which has been scaled down to size that is difficult to discern much meaning from.
Again, I urge you to re-evaluate the amount of information, and the value of that information, in the user layout and either return to the previous format or find a way to bring that utility into a further revision.