I received the same enthusiastic, exclamation point laden email about two days after submitting my application. I replied, and we set up an interview date a week off.
The interview was over the phone. No "jelly bean" question, or anything similar in terms of brain teasers/riddles. Either they cut this segment, or it was skipped for me because our call accidentally dropped and the interviewer has to call me back.
The process was about twenty minutes, and as mentioned before, they seemed to read from a script, without really following up on answers or digging deeper. They also seemed more eager to set up the art test.
There was an art test; draw two animals in the In House Style in a week's time or less. I did so in about four days, and received a "Thanks, our art director will review" type reply. A few days later, I got the same decline email the other Illustrator position review mentioned. No offer.
I am skeptical of IXL, because their general customer reviews are extremely low. Students seem to hate their products beyond the general Tween Hates Studying caliber. That aside, during the application and interview process, they give the impression that there is SO much art to be taken on. There are HUNDREDS of pictures that need to be created or edited-- that is the case, and yet I haven't seen a single person receive a job offer.
I share the concern that they use the "art test" artwork on their website. Unlike the applicant that mentioned being offered $200 for the spec work, I was offered nothing.
That said, I sent a follow up email to the interviewer to 1. ask for feedback on my test, and 2. get it down in writing that they will NOT use my art anywhere, since I wasn't compensate, and didn't get the job.
They replied that it was "against their policy" to give feedback (uhhh, okay?), but did assure me that my work would not be used anywhere by them, and fully belonged to me.
Overall-- A waste of time.
Good luck to other applicants.