A monocle is a visual aid with only one glass. At the end of the 19th century it was a status symbol. Something seems suspicious! The smiley makes a warning look around. The "upper-class" version of the pondering smiley.
The face with monocle emoji was introduced in 2017 and released as part of the Unicode 11.0 standard. This emoji can be found under the smileys and emotions
category. Because the face with monocle emoji has been around for quite some time, it should display correctly in the majority of operating systems.