Sideways White Up Pointing Index

It's a plain text symbol, not an emoji. Your font draws it, so it may look thin, bold or slightly different from one device to another, and some phones show an empty box if no installed font has it. There is no colourful emoji version.

It entered Unicode so that documents written with Microsoft's Wingdings symbol fonts, which offer pointing hands in several directions, keep their pictures when converted to ordinary text. Its siblings point other ways, such as 🖟.

Why do pointing hands appear in text at all?

Printers have used them as markers for centuries. Medieval readers drew small hands in margins to flag important passages, and printers turned that into a type sign called the index or manicule, as in ☞. In a message or a note, 🖞 does the same job: "look here". Add a few words if the reader needs to know why.