No, the details of the cake where never discussed.
“Masterpiece's owner Jack Phillips, who is a Christian, declined their cake request, informing the couple that he did not create wedding cakes for marriages of gay couples owing to his Christian religious beliefs, although the couple could purchase other baked goods in the store. Craig and Mullins promptly left Masterpiece without discussing with Phillips any of the details of their wedding cake.” https://en.wikipedia.org/wiki/Masterpiece_Cakeshop_v._Colora...
It might actually be 100% legal to reject providing gay themed decorations while providing a cake
“Masterpiece's owner Jack Phillips, who is a Christian, declined their cake request, informing the couple that he did not create wedding cakes for marriages of gay couples owing to his Christian religious beliefs, although the couple could purchase other baked goods in the store. Craig and Mullins promptly left Masterpiece without discussing with Phillips any of the details of their wedding cake.” https://en.wikipedia.org/wiki/Masterpiece_Cakeshop_v._Colora...
It might actually be 100% legal to reject providing gay themed decorations while providing a cake