Unrevealed object opacity
In Display Settings, you can pick how you want the available objects to appear. You can choose between 0% and 30%. When an object has been donated (or revealed), it will be displayed at 100%.
If you want your page visitors to be able to see where they are all the objects are hidden, choose a higher percentage. This will allow visitors to select their favourite object on the page.
Alternatively, you might choose to make all the objects invisible (0%), so that they are only revealed after a contribution has been made.