I often think the impotence of a make up artist is overlooked by many models on shoots. A lot of time models will say that they do there own makeup. but Professional Knowledge is key, MUA have the product knowledge to know what works on camera, the also know what works with different skin types.
The above picture shows a before and after from makeup the difference is staggering. This kind of makeup and the skill of the MUA will make the photographers editing and post process time a lot less
finished Image with professional makeup and little post process editing think you will have to agree the final image is stunning