There are two types of orangeries, solid roof orangeries have a flat roof constructed around all the walls of the room using steel and timber in a traditional build and usually around 800mm in width. The glazed area is then a separate roof to the flat roof,this is a true orangery.
A mock orangery is when a conservatory roof is adapted to look like a orangery but only on the inside, this cuts out the need for the steel and timber flat roof and is much more cost effective. The internal look is created to allow for spotlights and plaster finish and gives theeffect of an orangery. I have separated the pictures to show the difference. Both designslook great, it's just a matter of personal preference.