Firstly, by having your mannequin close to the wall, your camera has kept the mannequin in focus and the wall in focus. That is distracting. You can get the wall out of focus by bringing your mannequin away from the wall, then choosing a wide aperture (number around f/2, f/2.8, f/4) and focussing on the mannequin.

Secondly, the shaded location means that your mannequin is not producing many shadows. This is because the light in that location is diffuse - it is lighting your subject from all directions relatively equally. To create a shadow you need light to be stronger in one direction rather than another. To alleviate this, you could be tempted to go with sunlight, but that will cast a very strong shadow and that is usually not desireable either. My suggestion is to use a flash. To acheive this you could use a "speedlight" (which is the flash unit you plug in to the top of your camera) but put it on a tall tripod above and to the left or right of your mannequin. You will also need a remote trigger - this comes in a kit with two items: one will connect to the flash (that's on the tripod) and the other will plug into the top of your camera. When you fire your shot, the trigger will fire your flash. If you leave it at that, the flash will produce strong shadows. This is called shooting "bare head" with the flash. You could put a small portable softbox, designed for speedlights, on the flash. This will diffuse the light slightly and make the shadows gentler.

If you don't have budget or time to buy new gear, then consider shooting indoors instead, and have a large window to one side of your shoot. The window will spread diffuse light on your mannequin from the side. If direct sunlight is still creating shadows that are too strong, then hang a light white fabric over the window.