Blocking my shawl

I blocked my shawl on a towel on the carpet, by pinning it out and spraying it with water.  Once the shawl was dry the lace pattern on the edge was more defined.  The top of the shawl was meant to be straight but was tight and so I had to curl it up as you can see.  I slipped the first stitch each time and maybe that was the problem.  Perhaps someone can tell me what I did wrong!