We have three sizes here: normal/normal, half/normal, and normal/half. The first part is how thick it is, the second part is how wide it is. You can see that the thinnest one is the most colored inside, but then you realize it is an optical illusion due to my phone camera taking a bad photo and my cleanup attempts failing. The half/normal came out the crumbliest, and the normal/half and normal/normal were indistinguishable. Remember, the goal for shortbread is to cook out most of the butter so it becomes crumbly instead of mushy. Here is my pinky for reference. And, yes, these things are small.
On the left we have pre cooking, and on the right post-cooking. They do plump a little in the oven, and lost a little bit of their shape. The important bit is letting them cool completely - they are actually best the next day (or, at least a few hours after baking) instead of fresh out of the oven like most cookies are. Yay for not during myself!