When an own background is the right choice
Studio white and grey keep the attention on the garment and suit a product gallery. A background chosen by the brand does a different job: it places a collection in a context the customer recognises, such as the floor of a boutique, a showroom wall, a texture used across the brand's packaging, or a street that belongs to the label's story.
It is also a route to consistency across a season. A campaign shot on location by a photographer can be continued with new products by photographing the empty location once and placing models into it, so later additions to the range sit in the same place as the first shoot rather than in a generic scene.
How the scene and the model are combined
The background photo is supplied as a reference of its own next to the garment photo. The brief asks for the subject to be placed in that scene, matching its perspective, horizon and lighting direction, and forbids redrawing or restyling the scene. The garment rules are unchanged: the product is briefed to keep its colours, shape and details as photographed, and pose and model work as on any other background.
The light settings belong to the described locations and do not apply here; the light of the supplied photo is the light of the image. A photo taken at golden hour gives a warm image, and an interior under mixed lamps passes on that colour cast too. Correct the colour of the background photo before it is uploaded, not afterwards in each delivered image.
What to look for in the delivered image
Look at the feet first. A standing model has to meet the floor of the scene: shoes resting on it, a shadow falling the way other shadows in the photo fall, the size of the person plausible against doors, chairs and steps. A model that seems to float, or towers over a doorway, is a sign that the background photo had too little floor or too steep an angle.
Then compare the garment with the real piece, as with any try-on: colour under the scene's light, prints, buttons and fine edges such as lace or fringe. A strongly coloured light in the scene can tint the garment in the image; if the colour drifts, a plainer background photo taken in neutral daylight is the better source.