When there are text properties on the char, `describe-char' (hence also
`C-u C-x =') shows each of them using the button `[Show]'.
 
1. A user must click each button to see the value.  And if buffer `*Pp
Eval Output*' happens to be a special-display buffer then it is shown in
a separate frame.  
 
This might be appropriate for some values - e.g., values that are too
long to fit on a line of the standard max length for `*Help*', but it
does not make much sense for values that are not too long.  It just
means more work and annoyance for the user.
 
2. If you then do, say, `C-h f forward-char', so that `*Help*' now shows
something different, and then you click `[back]', you get the previous
`describe-char' output, but this time all of the `[Show]' fields have
been replaced by their values.
 
See the attached screenshots.
 
What you see in #2 should not be different from what you see in #1.  And
what you see in #2 is in most cases more user-friendly: most such values
can be shown completely on the same line - there is no need to force
users to futz around with `[Show]' buttons.
 
Please DTRT for users:
 
a) Show all values that can be shown on the same line, instead of
using`[Show]' buttons for them.
 
b) Show the same output initially and when `[back]' or `[forward]' is
clicked.
 
In GNU Emacs 24.0.92.1 (i386-mingw-nt5.1.2600) of 2012-01-22 on MARVIN
 Windowing system distributor `Microsoft Corp.', version 5.1.2600
 configured using `configure --with-gcc (4.6) --no-opt --cflags
 -ID:/devel/emacs/libs/libXpm-3.5.8/include
 -ID:/devel/emacs/libs/libXpm-3.5.8/src
 -ID:/devel/emacs/libs/libpng-dev_1.4.3-1/include
 -ID:/devel/emacs/libs/zlib-dev_1.2.5-2/include
 -ID:/devel/emacs/libs/giflib-4.1.4-1/include
 -ID:/devel/emacs/libs/jpeg-6b-4/include
 -ID:/devel/emacs/libs/tiff-3.8.2-1/include
 -ID:/devel/emacs/libs/gnutls-3.0.9/include --ldflags
 -LD:/devel/emacs/libs/gnutls-3.0.9/lib'