chocolate-box 
adjective British
(Of a view or picture) pretty in a conventional or idealized way: chocolate-box cottages lining narrow streets...
- This book celebrates that diversity in over 140 superb photographs that go beyond the traditional chocolate-box images to delve deeper into the fundamental character of the Lakes.
- These traditional cottages are not only chocolate-box pretty, they also provide good levels of natural insulation - but don't forget the repair and renewal costs
- The chocolate-box image of Mozart as a little miracle can be promptly banged on the head.
Origin
From the use of attractive images to decorate boxes of chocolates.