sharing.php

<option
<?php if ( $global['button_style'] == 'icon-text' ) { 
  echo ' selected="selected"';
}?> value="icon-text"><?php _e( 'Icon + text', 'jetpack' ); ?></option>

<option
<?php if ( $global['button_style'] == 'icon' ) { 
echo ' selected="selected"'; 
} ?> value="icon"><?php _e( 'Icon only', 'jetpack' ); ?></option>

<option
<?php if ( $global['button_style'] == 'text' ) { 
echo ' selected="selected"';
}?> value="text"><?php _e( 'Text only', 'jetpack' ); ?></option>

<option
<?php if ( $global['button_style'] == 'official' ) { 
echo ' selected="selected"'; 
}?> value="official"><?php _e( 'Official buttons', 'jetpack' ); ?></option>