Here’s a good example of effective social media content by Phill Mason. It ticks some big boxes which has contributed to it’s viral spread:

• It’s highly visual – optimised for photo sharing, simple message.
• It’s “on brand” – relevant to their core business and their value proposition.
• It’s emotive – Tasmanian’s can take pride in this and make it their own by sharing with friends.

Beyond that it’s super simple!  I like it.