Your little bird brooches are so adorable! Question - is the card with the tree behind it part of the brooch or just the packaging? I am guessing its part of the packaging, which is also just adorable!! But, because all your photos in some of your listings include that background, a buyer might assume the card with the tree illustration is part of the brooch itself.
I would take some pictures of just the bird and use just one picture of the bird on the packaging card as your last photo only. Because your packaging really is a cute selling point!
The moss is a fun background, but slightly overwhelming. You want your bird to be the focus of the picture and nothing else to compete with it. You also want a neutral background that will allow the colors of the birds to "pop". I would try doing some pictues on a simple paper background - scrapbook paper works great. Maybe something in a neutral beige color with a little texture. Burlap or linen fabric might look really cute too.