> You did that only for a single character SHIN?  But the image shows
> that the entire string is displayed by a font that is not DejaVu Sans
> Mono.  And at least on my system, DejaVu Sans Mono doesn't have glyphs
> for the Hebrew block, so when I tell Emacs to use DejaVu Sans Mono as
> the default font, the Hebrew letters are displayed using a different
> font.
>
> If you don't apply the text property, do you see the Hebrew text
> displayed by DejaVu Sans Mono, or does Emacs use a different font for
> it?  And what does describe-char say about that if you don't apply the
> text property?
>
> > Apparently, this is what is causing the issue.
>
> It could be, but I don't see how this could happen, by just looking at
> the code involved in this.  I'm probably missing something.
>
It is "emacs -Q". My default font is DejaVuSans Mono. Hence H is displayed
using the same. The Hebrew text is using Linux Libertine Display O. For
printing, I needed text with font variation. So I applied the text property
for weight and slant - though it didn't change the appearance. After that,
desc-char starts reporting as mentioned in OP.