Irish Rose Crochet Square

I'm waiting on somebody to post an answer to a question I asked so I thought I'd go ahead and post my green rose! This is for the March Craftster 12" crochet block. The pattern is called "Irish Rose" by Ferosa Harold (I'm not sure how to link to it other than through Craftster because the "host" made some corrections and posted the pattern herself rather than give a link to the pattern).

Anyway, it wasn't too difficult after I saw yellowduckie's YouTube video (http://www.youtube.com/watch?v=fRG0mS8-NeU) for how to crochet between the rose petals.

Now, though, I don't understand part of how to make the square that goes around the rose. I know how to make the shell stitch, but had to post a question for what does "shell in shell" mean? Does it mean in the SPACE from the previous round or what?


The pattern calls for a "H" hook, but I'm using a 5.5mm/I hook instead. I hope that's not too big.