Seems a great deal. Ensure you're logged in if buying online else the code won't work. Stay safe, and enjoy.
Gift voucher is single use only, and must be presented to receive discount. Save $20 off your total transaction (min spend $20). Not to be used in conjunction with additional voucher or team member discount. Excludes all electrical appliances, sewing machines, overlockers and paper craft machines, new & existing made-to-measure orders & payments, everyday bargains, clearance items, existing laybys & gift cards. Not to be used in conjunction with any other voucher, coupon or team member discount.
Edit1: Code 10CELEBRATE appears to work as well for $10 off $10 spend (thanks turk182).
Edit2: Code 15CELEBRATE appears to work as well for $15 off $15 spend.
Wasn't able to use the image on my phone at Spotlight Frankston, have to show them that you actually got the email. They said it's because people who didn't receive the email are trying to use the voucher. Just showing them your VIP card isn't enough. Obviously not the same at all stores but that's what's happening there!