This is an helper function for org-download. It creates an \"./image\" folder within the same directory of the org file. Images are separated inside that image folder by additional folders one per org file.

drestivo-org-download-method.el

(defun drestivo/org-download-method (link)
  "This is an helper function for org-download.
It creates an \"./image\" folder within the same directory of the org file.
Images are separated inside that image folder by additional folders one per
org file.
More info can be found here: https://github.com/abo-abo/org-download/issues/40.
See the commit message for an example:
https://github.com/abo-abo/org-download/commit/137c3d2aa083283a3fc853f9ecbbc03039bf397b"
  (let ((filename
         (file-name-nondirectory
          (car (url-path-and-query
                (url-generic-parse-url link)))))
        (dir (concat
              (file-name-directory (buffer-file-name))
              (format "%s/%s/%s"
                      "images"
                      (file-name-base (buffer-file-name))
                      (org-download--dir-2)))))
    (progn
      (setq filename-with-timestamp (format "%s%s.%s"
                                            (file-name-sans-extension filename)
                                            (format-time-string org-download-timestamp)
                                            (file-name-extension filename)))
      ;; Check if directory exists otherwise creates it
      (unless (file-exists-p dir)
        (make-directory dir t))
      (message (format "Image: %s saved!" (expand-file-name filename-with-timestamp dir)))
      (expand-file-name filename-with-timestamp dir))))

(setq org-download-method  'drestivo/org-download-method)