I write an advice for this.

#+begin_src emacs-lisp

;; `org-plot/gnuplot' advice of auto insert org gnuplot result image file.
(advice-add 'org-plot/gnuplot :around #'org-plot/gnuplot-insert-org-image-link)

(defun org-plot/gnuplot-insert-org-image-link (origin-func &rest args)
"Auto insert `org-plot/gnuplot' generated plot image file link."
(save-excursion
(org-plot/goto-nearest-table)
;; Set default options.
(setf params nil)
(dolist (pair org-plot/gnuplot-default-options)
(unless (plist-member params (car pair))
(setf params (plist-put params (car pair) (cdr pair)))))
;; Collect options.
(while (and (equal 0 (forward-line -1))
(looking-at "[[:space:]]*#\\+"))
(setf params (org-plot/collect-options params))))
(setf param-file (plist-get params :file))
(apply origin-func args)
(goto-char (org-table-end))
(org-indent-line) (insert (format "\n"))
(org-indent-line) (insert (format "[[%s][%s]]" (expand-file-name param-file) param-file))
(org-indent-line) (insert (format "\n"))
(when org-startup-with-inline-images (org-redisplay-inline-images)))

#+end_src

I suggest `org-plot.el` library can support this feature.

[stardiviner] <Hack this world!> GPG key ID: 47C32433
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On Sun, Jun 18, 2017 at 1:55 PM numbchild@gmail.com <numbchild@gmail.com> wrote:

I want to auto insert inline image for `org-plot/gnuplot` result plot below the table. Like this:

```org
#+PLOT: title:"Citas" ind:1 deps:(3) type:2d with:histograms set:"yrange [0:]"
| Sede | Max cites | H-index |
|-----------+-----------+---------|
| Chile | 257.72 | 21.39 |
| Leeds | 165.77 | 19.68 |
| Sao Paolo | 71.00 | 11.50 |
| Stockholm | 134.19 | 14.33 |
| Morelia | 257.56 | 17.67 |

Press =[C-c " g]= on upper table to generate gnuplot plot image (*NOTE*: the
generated plot image is in currently working directory).

#+ATTR_ORG: :width 250
#+ATTR_LATEX: :width 2.5in
#+ATTR_HTML: :width 250px
[[file:org-plot.png]]
```

I have an idea, add an advice on `org-plot/gnuplot` with a user helper function to inser the inline image link.
This advice need to:

- locate point below the table.
- get the `org-plot/gnuplot` result plot image link.
- insert inline image link.

[stardiviner] <Hack this world!> GPG key ID: 47C32433
IRC(freeenode): stardiviner Twitter: @numbchild
Key fingerprint = 9BAA 92BC CDDD B9EF 3B36 CB99 B8C4 B8E5 47C3 2433
Blog: http://stardiviner.github.io/