Emoji is dead tired and would love to sleep now. The bubble emerging from the nose is a typical manga symbol for a sleeping character. Or as an expression that a conversation or excursion is extremely boring and drowsy.
The sleepy face emoji was introduced in 2010 and released as part of the Unicode 11.0 standard. This emoji can be found under the smileys and emotions
category. Because the sleepy face emoji has been around for quite some time, it should display correctly in the majority of operating systems.