When a user clicks on a mood, they can pick between several emoticons. After the emoticon is picked, they can then manually type in a written 'mood', separate from the emoticon, into the text field.
In your case, this user clicked the 'unhappy' emoticon face, but then typed in "I'm Happy' into the text field. This was likely accidental on the user side, but the topic page reflects the smiley emoticon as the mood, regardless of the user had typed into the box.
I hope that explains what has happened. Apologies for the confusion!