I also have a (yet different) version of the robot rendered in my browser (Firefox on Ubuntu). I'm sure it is due to the font, which is monospaced but which probably doesn't include all the Unicode code points that you are using in your image.
Which is one of the weaknesses of using Unicode characters in "ASCII" art---anything outside ASCII itself risks being missing in monospace fonts. Some of it is pretty well guaranteed (like the DOS-pedigreed box-drawing characters), but a lot of that is going to vary from system to system to system depending on just what fonts are installed.
Perhaps you could have an option to render only a common subset of characters? Otherwise the central premise of the tool is substantially undermined.
Which is one of the weaknesses of using Unicode characters in "ASCII" art---anything outside ASCII itself risks being missing in monospace fonts. Some of it is pretty well guaranteed (like the DOS-pedigreed box-drawing characters), but a lot of that is going to vary from system to system to system depending on just what fonts are installed.
Perhaps you could have an option to render only a common subset of characters? Otherwise the central premise of the tool is substantially undermined.
EDIT: To illustrate (and maybe help debug), the version on mine looks like this: http://i.imgur.com/WI4eRLo.png