A SiFe type can also take the role of a "clown" of sorts to ensure all people are emotionally light and comfortable. SiFe types are also capable of creating an intimate open atmosphere where others can be comfortable sharing their emotions or talking about their problems. SiFe types also tend to mirror and heighten the emotions experienced by the group dynamically.
SiFe types are generally unable to conceal their feelings because their faces are so emotionally expressive. They display their comfort and discomfort vividly, and can often be seen wearing the widest smiles or the longest frowns.
Source - wikisocion.github.io