Wow - all these great comments - thank you to everyone who commented. Can not believe I could only scored overall a 4.396. The cactus is actually this color. But I do see how if you didn't know the actual color of the cactus - it could be viewed as "over-exposed", "washed out" or harsh lighting. The learning curve continues.
Needs to come in sharper. A bit more color contrast would help too, as the green in this shot seems rather washed out. I do like the composition and the idea here a lot though.