It's an emoji thumbs-down. You should be able to see it using Safari or Firefox on OS X. There is an outstanding Chrome issue related to this: https://code.google.com/p/chromium/issues/detail?id=62435

Available here [1] on page 18, or just look for "1F44E". I found the twist really clever, and first thought the author had simply used a generic block.

I didn't spend much time reading the cited document, but it looks like some existing glyphs may be merged with newer ones under certain conditions. What a mess... I feel Unicode has tried to compass way too many things (even italics!). Go figure...

[1] http://www.unicode.org/L2/L2011/11149-webdings.pdf

On Windows and with Chrome, yes.

On iOS 7.0.1 it's a colorful thumbs down.

Internet Explorer 11 shows a black/white thingie which might be a thumbs down with a lot of imagination. Firefox shows the same bitmap.

You need a font which supports emoji. Android, iOS and Mac OS X should support it out of the box, on Linux I had to install a font. I'm not sure what the situation is on Windows.

It's a Unicode thumbs down sign. You must not have any fonts with that glyph. It works fine for me in both Firefox 27 and IE 11 on Windows 8.1

I'm pretty sure that's intented