The WordPress formatter automatically converts certain text into Smilies. These Smilies are images and when included in post or comment, they are having the same style as that of other post images. In case you need to style them differently, the smiley images in WordPress are automatically given a CSS class of ‘wp-smiley’ when they are displayed in a post. You can use this class to style your smileys differently from other post images.
For example, in order to give left margin to smiley images, you can use the following CSS code
[recommended]You may like to read: List of Smilies Available In WordPress Default Installation[/recommended]