I suggest to use font-at to get the font-object you need for
font-get-glyphs.
I had already used that and got
#<font-object "-GOOG-Noto Sans Kaithi-regular-normal-normal-*-23-*-*-*-*-0-iso10646-1">
but font-get-glyphs was not accepting it.
So the character is actually visible, it is just displayed as a thin
space. Which means that either its glyph in the font is like that, or
that the font lacks a glyph for it. What does "C-u C-x =" say when
the cursor is on that thin 1-pixel space?
position: 89 of 89 (99%), column: 0
character: (displayed as ) (codepoint 69821, #o210275, #x110bd)
charset: unicode (Unicode (ISO10646))
code point in charset: 0x110BD
script: kaithi
syntax: w which means: word
category: L:Strong L2R
to input: type "C-x 8 RET 110bd" or "C-x 8 RET KAITHI NUMBER SIGN"
buffer code: #xF0 #x91 #x82 #xBD
file code: #xF0 #x91 #x82 #xBD (encoded by coding system utf-8)
display: by this font (glyph code):
ftcrhb:-GOOG-Noto Sans Kaithi-regular-normal-normal-*-23-*-*-*-*-0-iso10646-1 (#x48)
Character code properties: customize what to show
name: KAITHI NUMBER SIGN
general-category: Cf (Other, Format)
decomposition: (69821) ('')
There is an overlay here:
From 89 to 90
face hl-line
priority -50
window #<window 3 on *scratch*>
There are text properties here:
fontified t
rear-nonsticky t
In the character section the character is not displayed in emacs but displayed in firefox, but it is displayed in the decomposition section in emacs. I have attached the images
Opening the font file in font forge also shows their glyphs