What is the difference between {Emoji_Presentation} and {Extended_Pictographic}?

Question

The top answer to the question "How to detect emoji using javascript" uses Extended_Pictographic.

Emoji_Presentation is mentioned in this blog post by David Walsh.

Answer 1

The Extended_Pictographic property is defined in Unicode Technical Standard #51, Unicode Emoji, and is primarily intended for use in line breaking and other segmentation algorithms.

The Emoji_Presentation property is also defined in UTS #51. It was created to help applications pick a default presentation when encountering certain Unicode characters: as monochrome text or as full-colour emoji. The need for this arose as a result of a decision made when emoji were first encoded to unify emoji used in Japan with existing Unicode characters when there was an existing character matching an emoji. (In hindsight, that might not have been the best decision because of this issue.)

Note that Extended_Pictographic is a property of Unicode code points, and that there are code points that are not (yet) assigned to any character. You can see a listing of all Extended_Pictographic code points grouped by their Emoji_Presentation (character) property values at https://util.unicode.org/UnicodeJsps/list-unicodeset.jsp?a=%5B%3AExtended_Pictographic%3A%5D&g=Emoji_Presentation&i=. (This shows them sub-grouped by blocks.)