I actually think this is a bug: if you click on an image in IBY and bring up the filmstrip view (single large image and a stripe of images at bottom), when you click the heart filter at top nothing happens when it should be filtering like happens when click same button in the contact sheet (initial thumbs overview) view. You can also filter favorites by a checkbox once add to my cart, making filmstrip the only non-filterable view of the three for now. Can't see good reason it should be left out. If a customer, I'd want to make favorites and then look at them closely only in strip view after an initial first pass over contact.