Exercise: Object in different positions at the frame

Camera body: Nikon d90
Lens: Nikkor 70.0-300.0 mm f4,0-5,6
Shutter speed:1/800" 
Aperture: f/5,6
ISO 1250

 Camera body: Nikon d90
Lens: Nikkor 70.0-300.0 mm f4,0-5,6
Shutter speed:1/800" 
Aperture: f/5,6
ISO 1250

 Camera body: Nikon d90
Lens: Nikkor 70.0-300.0 mm f4,0-5,6
Shutter speed:1/1000" 
Aperture: f/5,6
ISO 1250

 Camera body: Nikon d90
Lens: Nikkor 70.0-300.0 mm f4,0-5,6
Shutter speed:1/640" 
Aperture: f/5,6
ISO 1250

Camera body: Nikon d90
Lens: Nikkor 70.0-300.0 mm f4,0-5,6
Shutter speed:1/1000" 
Aperture: f/5,6
ISO 1250

For this exercise, I’ve chosen a sheep as the subject. Its white color makes a difference with the green grass, which takes the most part of the image. 

I’ve chosen different compositions, starting with centering the sheep. In my opinion this one doesn’t work very well because it makes it static. The second composition is which I like most, because part of the background can be seen so it helps to place the sheep and balance the composition. In the third picture I followed the rule of thirds, but I prefer the previous one, because this picture is a little boring in my opinion, too much grass.

In the next one, the sheep is on the bottom of the picture, centered. I don’t really disklike it but I don’t feel really comfortable with it neither. And in the last one, the subject is placed in the top left corner of the image, leaving too much space empty.