Hi. It looks like the image was not attached in your post. I researched and found similar posts that has the image. Here's my answer to your question.
In the above painting, the message that the artist, Antoine-Jean Gros, was trying to spread was that Napoleon was like Christ figure who healed the sick with his touch. Napoleon asked Gros to paint him the portrait which will help him in his political career.
I hope this is the answer that you are looking for.