2. C-a C-u C-x =

--8<---------------cut here---------------start------------->8---
             position: 146 of 146 (99%), column: 0
            character: ش‎ (displayed as ش‎) (codepoint 1588, #o3064, #x634)
              charset: unicode (Unicode (ISO10646))
code point in charset: 0x0634
               script: arabic
               syntax: w 	which means: word
             category: .:Base, R:Right-to-left (strong), b:Arabic
             to input: type "C-x 8 RET 634" or "C-x 8 RET ARABIC LETTER SHEEN"
          buffer code: #xD8 #xB4
            file code: #xD8 #xB4 (encoded by coding system utf-8-unix)
              display: by this font (glyph code)
    xft:-PfEd-DejaVu Sans Mono-normal-normal-normal-*-19-*-*-*-m-0-iso10646-1 (#x46A)

Character code properties: customize what to show
  name: ARABIC LETTER SHEEN
  general-category: Lo (Letter, Other)
  decomposition: (1588) ('ش')

There are text properties here:
  fontified            nil
--8<---------------cut here---------------end--------------->8---

3. SPC

The "tail" of the sheen becomes visible, but falls outside of the box
cursor: