Leftwards Right-Shaded White Arrow

A hollow left arrow with a drop shadow on its right. "White" in the name means outlined, not filled; "right-shaded" means the dark edge sits on the right, the tail end. The shadow gives the flat arrow depth, the look of an old-style toolbar button. In a message, a slide or a document it simply says "back", "previous" or "see the thing on the left"; it carries no emotional tone.

It belongs to a set of eight shaded white arrows: left and right, each with the shadow on the top, bottom, left or right. They come from Wingdings, the symbol font family Microsoft shipped from Windows 3.1 in 1992 onward. For years those arrows were only font tricks: a letter typed in Wingdings turned into a picture, and switched to another font it turned back into a letter. A 2011 proposal asked Unicode, the world standard for text characters, to give them real codes of their own, so they survive copying, searching and font changes.

Why does it look different, or not show at all?

Your font draws it, and many fonts don't include it. Each font paints its own version, so the thickness and the size of the shadow vary. If you see an empty box or a question mark, the device has no font with this arrow; the character is still there and will appear on a device that has one. For something everyone can see, use the plain ← or ⇦.