All right, this is a bit of an in-joke. I'll make it as brief as possible.
It all started when MewFushi (https://www.deviantart.com/mewfushi) was looking at a Gensoumaden Saiyuki doujinshi. Put together a doujin page and a screenshot of Konata, and there you go: http://i159.photobucket.com/albums/t136/FushiFushiFushi/goodjob.jpg
The gag was later extended by hajike-no-tori (https://www.deviantart.com/hajike-no-tori) to include a picture of Gojyo in a speedo. [also link] (That's why it's spelled "jyob" rather than "job", you see.)
Now "Good Job!" has its own plz account. Use this icon whenever you wish, be it Lucky*Star-related, Saiyuki related, or just, in general, a Good Job.
Also, if anyone comes up with a