Hmm... I think that many times I have problem to submit a Buildings pictures.. I cannot decide whether they are objects or places. Or parts of buildings.. such as windows and doors or stairs.
Plants : Flowers, Trees, Grass and macro ? Macro category is way too general.. you can make a macro of almost anything.. maybe adding Macro into each category? Animals: adding such as type of animals is a great idea by ~Fobtrix-Stock Household items, maybe divide into : Kitchen, Living room, Bathroom, Dining room, Corridor (or Hall) .. hmm.