From Damian Vila on Dribbble:
Dribbble has several shots of language selectors using flags — however this one raises awareness of the simple fact that flags symbolize nations and not languages.
A blog about designing global user experiences: beyond language, location & culture.
In theory you are right. It is a mistake to represent Languages by flags, as flags represent nations not languages.
Unfortunately you are wrong in practice. If someone don’t speek your language you cannt communicate by words, you need to use hands, feets or symbols. Unfortunately there are no known symbols for languages. So in practice the best way to guide your user to a content he understands is a symbol of a nation using these language. Your user will easily understand these well known symbol and can be guided to content he understand.
Check it out yourself. Open some chinese webpages (a.e. http://twtraffic.tra.gov.tw/twrail/TW_QuickSearch.aspx) – with a symbol navigation would be easier…
Communicating without words is a really a whole different conversation – this blog is really about presenting content/words online. The link you use as an example shows translation links in the top right presented in their local language name (i.e., English for English, 日本語 for Japanese) – this is exactly an approach I suggest and promote.