Your item probably changed from one state to another. In its place, there should be a new item that you have not seen before. Watch out -- your Experiment may morph again very soon! If the new item has a little “?” symbol in the lower right corner next to the image, keep an eye on it, because it’s going to morph again at some point. If there is no “?” symbol, then your Experiment has reached its final stage, and you should be able to find all of its previous item states in your Inventory (if not now, very soon).