Is there a users guide or something similar that describes in detail all the images that one sees on the display? There seems to be a lot of stuff there, but no explanation.
For most of the screens, you can find detailed descriptions in the Users Guide found on LEGO MINDSTORMS download page. Additionally, there is some information in the help file of the EV3 programming software.
The best resource I have come across that shows "everything", though, is the Apps > General Information: Userinterface section of the documentation from the lms2012 source code. The source code is officially available from the "Advanced..." section of the LEGO MINDSTORMS download page.
You can also find the compiled documentation hosted at http://ev3.fantastic.computer/doxygen/uiapp.html.
I've included the relevant images below as well in case links break.
Although this shows "everything" it does no have much in the way of detailed descriptions. On the other hand, it does provide some hints to some obscure things that are not documented anywhere else.