Currently, the image insertion button in the editor only inserts [[File:Example.jpg]] (it is localized - in Hebrew it's [[קובץ:דוגמה.jpg]]).
This button should also insert "250px|thumb|right|Description", to help users who don't know how to write it.
It was like this locally in the Hebrew Wikipedia, but the change to Vector overrode it. I believe that it's useful for projects in all languages.
The "thumb" and "right/left" parts must be localized, of course (Bug 24114 must not be repeated here). It must also consider the defaults for LTR/RTL - if i understand correctly, the default should be "right" for LTR and "left" for RTL (double-check it, because i suffer from [[Left/right confusion]] :).