Hello, the attached SVG file was made with M-x org-latex-preview.  It
includes an embedded PNG file.

The source is this LaTeX-in-Org oneliner, together with the PNG.

$$\mathit{Hello} \includegraphics[width=2cm,natwidth=445,natheight=661]{/home/joe/tools_for_thought/Tft1st.png}$$

The generated SVG image displays correctly in Mozilla Firefox 88.0.1.

However, inside Of Emacs 28.0.50 (2021-05-05, 31f64d), the image
displays, but I don’t see the embedded png file.  The PNG displays fine
in Emacs via M-x find-file.

Relevant config settigs:

(setq org-preview-latex-default-process 'dvisvgm)
(setq org-preview-latex-process-alist
      '((dvipng :programs
                ("latex" "dvipng")
                :description "dvi > png" :message "you need to install the programs: latex and dvipng." :image-input-type "dvi" :image-output-type "png" :image-size-adjust
                (1.0 . 1.0)
                :latex-compiler
                ("latex -interaction nonstopmode -output-directory %o %f")
                :image-converter
                ("dvipng -D %D -T tight -o %O %f"))
        (dvisvgm :programs
                 ("latex" "/usr/local/texlive/2021/bin/x86_64-linux/dvisvgm")
                 :description "dvi > svg"
                 :message "you need to install the programs: latex and dvisvgm."
                 :image-input-type "dvi" :image-output-type "svg"
                 :image-size-adjust (1.7 . .1)
                 :latex-compiler
                 ("latex -interaction nonstopmode -output-directory %o %f")
                 :image-converter
                 ("/usr/local/texlive/2021/bin/x86_64-linux/dvisvgm %f -n -e -c %S -o %O"))
        (imagemagick :programs
                     ("latex" "convert")
                     :description "pdf > png" :message "you need to install the programs: latex and imagemagick." :image-input-type "pdf" :image-output-type "png" :image-size-adjust
                     (1.0 . 1.0)
                     :latex-compiler
                     ("pdflatex -interaction nonstopmode -output-directory %o %f")
                     :image-converter
                     ("convert -density %D -trim -antialias %f -quality 100 %O"))))