Thomas rescues his dog, Milo when a group of party guests tie him to a set of balloons and send him afloat, Thomas is heard yelling "That's my
dog". Kirby remarks that she should record the event. Seconds later she shows Thomas the recording inside the house and you can hear Thomas yelling "That's my dog" which he said before she started recording.
Before party starts the boys are in Thomas's bedroom and his Dad calls for Thomas. Thomas and Costas run out and there is no skateboard between mirror and piano. Then when Dax films himself in that mirror you see the piano and a skateboard appears.