The art of decorating refers to the taking of a space, four walls and a roof. Decorating art also aims to make the room look better or fill the room with items and accessories. The purpose of decorating is to make the room more beautiful which can give your guest a good impression about its style and sophisticated look.
So this begs the question: since you are taking a space and doing things to make it look better than it actually is... is home decorating a form of lying?
In a crude sense all art is a lie. Every time we try to represent something which isn't really there, we are creating an illusion. It is an act of deception, which is not necessarily antagonistic. Instead it is often meant to delight the senses with the intrinsic beauty that is called up by the successful application of this act.
If you say that decorating is a lie, then you should also count paintings, music, movies, and books all as mediums for liars. To some extent, this is a fair comparison. They are all dealing with alternate realities, things which do not exist, or which exist elsewhere, independent of the actual media being employed.
On the other hand however, the point of art is to create beauty. As such, isn't art the truest thing possible? Beauty is something which touches all humans, regardless of location, culture, or upbringing. We may have differing opinions as to what specifically constitutes beauty, but we all understand its true nature deep within our conscious beings.
In this way, decorating is just a matter of taking concepts of beauty, a universal idea, and applying them to the world around us. This means it is not really a lie, but merely a revelation of the potential that exists within every space, every moment, every object in the world around us.