Towards the end of the episode, when Izzie and Alex argue inside the trailer and then Izzie hugs him, you can see her blonde hair underneath the scarf she's wearing. She's supposed to have shaved her head because her hair was falling due to chemotherapy.
From 4:40 - 5:35 Grey and Yang are eating ice lollies whilst Izzy is getting her chemo treatment, their ice lollies keep changing length depending on the camera shots. When camera is behind Grey it shows she's eaten quite a bit, but camera shot from the front the ice lolly is barely eaten.