Are they preparing for a bank robbery ?

You killed me. LOL
And Google Killed me back when I made the research to look after the answer ^^

Anyway, the correct answer is : it's a flymask (LOL -> like a super hero horse ?!)

A fly mask or fly cap is a mask used on horses to cover the eyes, jaw, and sometimes the ears and muzzle to protect from flies. The mask is semi-transparent and made from a mesh allowing the horse to see and hear while wearing it.... ---> WIKIPEDIA

Oh and by the way... about the ZEBRA.... It's just because we are never satisfy with who we are : we need to wear masks.