curl -i -L -X POST "https://api.box.net/2.0/users/12345/avatar" \
     -H "authorization: Bearer <ACCESS_TOKEN>" \
     --form 'pic=@"path/to/file/file.jpeg"'

{
  "pic_urls": {
    "small": "https://app.box.com/index.php?rm=pic_storage_auth&pic=euks! pac3kv01!7B6R5cZLmurEV_xB-KkycPk8Oi7oENUX2O_qUtIuO4342CG IldyCto9hqiQP7uxqYU5V2w63Ft4ln4UVVLDtDZu903OqzkflY2O-Lq00 ubA29xU-RJ6b_KzJEWRYgUhX1zEl3dzWo12g8eWRE2rStf123DF7AYahNqM 1BmLmviL_nODc7SDQHedTXPAjxURUAra5BvtLe7B05AizbNXdPlCNp-LNh _S-eZ_RjDXcGO-MkRWd_3BOMHnvjf450t5BfKoJ15WhEfiMlfXH1tmouHXrsC 66cT6-pzF9E40Iir_zThqSlrFxzP_xcmXzHapr_k-0E2qr2TXp4iC396TSlEw\n",
    "large": "https://app.box.com/index.php?rm=pic_storage_auth&pic=euks\npac3kv01!lipGQlQQOtCTCoB6zCOArUjVWLFJtLr5tn6aOZMCybhRx0NNuFQbVI36nw\njtEk5YjUUz1KVdVuvU2yDhu_ftK_bvxeKP1Ffrx9vKGVvJ-UJc1z32p6n2CmFzzpc\ngSoX4pnPhFgydAL-u9jDspXUGElr-htDG_HPMiE9DZjqDueOxXHy8xe22wbaPAheC\nao1emv8r_fmufaUgSndeMYmyZj-KqOYsLBrBNgdeiK5tZmPOQggAEUmyQPkrd8W92TQ6sSlIp0r",
    "preview": "https://app.box.com/index.php?rm=pic_storage_auth&pic=euks!\npac3kv01!8UcNPweOOAWj2DtHk_dCQB4wJpzyPkl7mT5nHj5ZdjY92ejYCBBZc95--403b29CW\nk-8hSo_uBjh5h9QG42Ihu-cOZ-816sej1kof3SOm5gjn7qjMAx89cHjUaNK-6XasRqSNboenjZ\n04laZuV9vSH12BZGAYycIZvvQ5R66Go8xG5GTMARf2nBU84c4H_SL5iws-HeBS4oQJWOJh6FBl\nsSJDSTI74LGXqeZb3EY_As34VFC95F10uozoTOSubZmPYylPlaKXoKWk2f9wYQso1ZTN7sh-Gc\n9Kp43zMLhArIWhok0Im6FlRAuWOQ03KYgL-k4L5EZp4Gw6B7uqVRwcBbsTwMIorWq1g"
  }
}