picture.js

/*
We presume here that the `Pictures` collection has _url_ and _name_ attributes.
*/
Template.mypictures.helpers({
  pictureAttributes: function(picture) {
    var pic = picture.hash.picture;
    return {
      url: pic.url,
      title: pic.name
    };
  }
});

pictures.html

<template name="mypictures">
  {{#each pictures}}
    <img {{pictureAttributes picture=this}} />
  {{/each}}
</template>