JavaFx TextArea doesn't display the Emoji and Symbols on dropping them on the text area, whereas Mac OS native app TextEdit displays the Emoji and Symbols.

Problem is observed on Mac OS 10.12.5

To setup for this:
System Preferences -> Keyboard -> Show Keyboard and Characters Viewers
should be checked.
Then there should be a Flag on the system bag (which is the input selection pulldown)

Focus on TextEdit and Click the flag, then Show Character Viewer. It should come up, and allow you to add emoji characters into the TextEditor.