;; always resize inline images to 300 pixels
(setq org-image-actual-width 300)
;; if there is a #+ATTR_*: :width 200, resize to 200, otherwise resize to 400
(setq org-image-actual-width '(400))
;; if there is a #+ATTR_*: :width 200, resize to 200, otherwise don’t resize
(setq org-image-actual-width nil)
;; Never resize and use original width (the default)
(setq org-image-actual-width t)