imgur is more about sharing a single photo or creating a meme. This is more about creating and sharing an album of photos. The features of SimpleNeat include things like reordering photos, custom urls for albums, easy downloading, and, eventually, easy printing or creating mugs or t-shirts.
It's more about that because those are the most used functions, it's very easy to upload an album, and you can re-arrange,and download them, the custom URL is not possible if you're scaling up that large.
This feels more family oriented than imgur. I know that sounds silly, and maybe at some point this will be overrun with meme's too, but in its current state I would rather use this to send an album to my grandma than imgur.