Oh yeah, I forgot about views in the Hot algorithm.
You get a lot of views from the New pages when your image first features. Also if you share a link to your image page on other social media like Reddit or Facebook (not just a copy of the image) those views will help your image get to the Hot pages. There is a message that pops up about sharing when you submit an image, the share button on the image page has buttons to share on Facebook, Twitter, Pinterest, Reddit, etc.
When your image is on the first page of New, it's actually in the Hot pages somewhere like Page 9999 or past that. As the image gets deeper and deeper in New, the views from those pages tapers off, but the image is rising in hot and the number of views from those pages starts rising.
I know the number or rate of views matters in getting to the Hot pages, not sure how much it helps. I've heard it's a very small input.
If an image is getting Hot, it seems to take about a day to rise up into the first 10 pages or so of Hot, where it goes from there depends mostly on the input from the community (votes, comments, etc.)