Yes, Outlook tries to make this particular smiley -- "

" -- and not any other ones like "

" -- look better.
It does this by using a character from the Wingdings font, which is always available on Windows, and the smiley character there is in at the position normally used by capital J.
Since Android (or Linux) doesn't have Wingdings, you get some other font, where a J is a J and not a smiley.