There are two ways to sort content in a newsletter:
1. Sequencing - By default, content will have a sequence of 0. If manually set, content will flow from top to bottom, left to right, with the lowest number appearing first, and the highest number appearing last. The sequence numbers do not have to increment by 1. For instance, if a newsletter has three pieces of content, with the sequences: 0, 10, and 12, the content will be ordered on the newsletter in the same as if they were sequenced as: 0, 1, 2. Meaning, if there's nothing scheduled to slots 1-9, there won't be white space on the newsletter for those empty sequence slots.
2. Scheduling time - If no sequence is set, or multiple pieces of content share the same sequence number, content on newsletters will be sorted from oldest to newest by default (within the scheduled section). For example, if you schedule the Promotion to the "Latest" section of Hotmail for 9am on the 28th, then schedule the Whitepaper to the same section for 10am on the 28th, the Whitepaper will appear below the Promotion on the newsletter.