In extenuating circumstances, how bad is using display:none; to hide things you don’t want on the desktop version of the site and do want on the mobile version or vice versa?
It seems legit to me. You can turn things ‘on’ and ‘off’ at will.
Obviously this will only work for photos or style elements because I think hiding text or huge parts of a site is not only stupid but it’s against Google guidelines and will count as duplicate content.
As long as its the exception and not the rule… what say you?
