Only the person you whisper to can hear what you say. However these commands do not describe what you said but how you act, how you feel and so forth. Displays a emote. A second form of emote that doesn't display a space between the player character and the emoted text. For example the command think That's boring will display juggler .
Smiley characters are abstract representations of an emotion described using normal text characters.
Other players know from that why you take so long to respond to their questions, for example. Staying connected to the MOO in such a case allows you to read what happened in the room while you were away. Setting a doing message is also a kind of MOO politeness. This command is a special case of an emote. You first see the command, then what you see yourself and then what other people will see.