Have you ever created a brand new shinny post only to be really disappointed how the thumbnail displays in your feed?
When composing a new post one of the bigger issues I've had is the cropping of the thumbnail. Unfortunately there's been a few times when a post has gone live and the thumbnail doesn't display beautifully how I'd like in the feed.
Here's my recommendation:
I'd like to purpose we add add a "thumbnail" preview feature. Implementing this would be extremely simple and I'm certain would save a lot of steemers headaches - and a pretty quick add. Alternatively down the road we could implement a self cropping tool which would give some additional robust functionality.
Quick mockup for additional preview feature