Transferring a picture onto a cake

I signed up for a cake decorating course at Bulk Barn. The Thursday before Easter we learned how to transfer a picture onto a cake. We had to come to class with a cake, one recipe medium consistency buttercream icing, and one recipe thin consistency icing (already coloured). First, we iced our cakes with thin consistency icing. Then, because Easter was coming up, the instructor handed out Easter pictures to put on our cakes. I chose to use the Easter egg one. We put a piece if parchment paper over the picture and traced over it in white decorating gel. 
Then we placed the parchment paper face down on the cake and lightly went over the picture with a small paint brush to make sure all the decorating gel would stick. Then we carefully peeled the parchment paper off and there was the picture drawn in decorating gel! After that, we filled it in with medium consistency buttercream in the colours of our choice.