With the current trend in headless covers one wonders if the models are paid less for the posing because their faces are not gracing the cover. I for one dont like this trend of cutoff heads on the covers, may as well just make them artsy fartsy covers with flowers. Though it think this trend is only in historicals at the moment. One wonders why only historicals,

They are controversial but some people enjoy them. When the heads are cut off, readers don't face the conflict of the model not fitting the character as written. I prefer the entire person myself but sometimes the concept works well. It all depends on the execution.

I hope to write a Cover Biography article later this year, featuring Cover Models, and I'll try to remember to ask the question. I don't believe they are paid less because it's the publisher's art department that decides how to use the illustrator's creation.