TinyWiki has a class called TWSmiley. Your WeatherPI code link leads to a page that is activating TWSmiley class>>#binaryShocked four times.
That is to say, every time the parser sees :0 it creates a round, blue gif of a shocked smiley. When you write in code {0:0.2f} the third and fourth characters are replaced with a blue smiley face.
Adding a space after the colon would probably fix that.
I guess Lukas Renggli was in all ways younger in 2004.
Chris