Hum.. they are def a lot bigger, bolder, softer and occupy more screen space. We always tried to keep them small because: 1. The post is the important part, not the reactions and 2. Lots of screens are really small and bigger buttons tend to get more on the way of content.  

 They are also not using pitch black for the background, which does help soften everything up.  

 but ruins battery life 

 you're an artist...i don't think most of us are bothered by this.

although a SCALEABLE interface like Telegram has would be cool