What's different and why?

I have changed my entire idea from the above image. This was a late night establishment, where I was 'brain storming' with ideas. I flitted between ideas which I then began focusing on the above; being Nature, Two People, Two Animals, Human and Animal and Earth. I chose these because I want to express Compassion throughout the world! BUT I then, when wanting to sketch, figured it didn't work as well as I thought it would. Therefore, I scrapped that idea and decided to just do one final one.

Here is the human heart illustration that is inspiring my human heart in the centre of my moon. I have chosen this heart because it clearly shows a 2D heart, which is what I'm aiming for now. I'm not sure whether or not I'd like to do the heart in colour or to illustrate the heart in Ink, because I want it to look effective/visually appealing. 

This is a quick sketch to represent where parts of my painting/illustration will go. The outside will be made up of yellow acrylic paint, brighter from the outside fading to the very dark blue on the inside. The moon will be a general illustration of the moon, painted in grey's and white's and blacks. Along side that, I'm not sure whether or not I want the heart to be coloured or not, which is definitely something to consider in the next few days.