(I'm sorry if this is not formulated very precisely.)
As a temporary workaround to Bug 28573 i added this to Print.css in he.wp:
This works, but only if the "justify paragraphs" option is disabled in the preferences. If it is enabled, the image is still aligned to the right, because the justify paragraphs takes over the definition in Print.css. This is the default, so it probably doesn't affect most users, but still should be fixed.
There's also another possibility - that i should have added something else to Print.css.