またエラー引きそうなので、自分用のメモも含めて。

環境

Homebrewでインストールしたpyenv上で動かしています。

python2.7.12
Pillow2.7.0

事象

importでコケる

>>> from PIL import Image
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/var/pyenv/versions/2.7.12/lib/python2.7/site-packages/PIL/Image.py", line 63, in <module>
    from PIL import _imaging as core
ImportError: dlopen(/usr/local/var/pyenv/versions/2.7.12/lib/python2.7/site-packages/PIL/_imaging.so, 2): Symbol not found: _PyUnicodeUCS2_AsLatin1String
  Referenced from: /usr/local/var/pyenv/versions/2.7.12/lib/python2.7/site-packages/PIL/_imaging.so
  Expected in: flat namespace
 in /usr/local/var/pyenv/versions/2.7.12/lib/python2.7/site-packages/PIL/_imaging.so

対処

これで直った

$ pip freeze | pip install --ignore-installed --no-use-wheel -r /dev/stdin

ここに詳しく書いてある
Import Error on El Capitain · Issue #1753 · python-pillow/Pillow