Geep, isn't that the tear off for a separate rendered image window?  Didn't think it would automatically save to file. 

michael_REMY: the purpose of the export image is to select what format you would like to save your render as.  There are better formats than just jpeg which is a lossy format, it doesn't retain pixel information readily when scaling and resizing.  BTW, there is nothing gentle about this forum, we're a rough and tumble group. He he.