Since the introduction of iPhone 4, Apple has completely changed the standard of sim trays. Prior to it, we were used to use normal sim cards that could fit almost on all smartphones. Now vendors from around the world have adopted to the same standard as well because it let them to make space for the bigger battery. The leaked parts from Nowhereelse.fr of sim tray have suggested that Apple would shift from micro sim to Nano sim in iPhone 5.
Undoubtedly, it would give Apple more space for even bigger battery. In addition to it, Apple is also expected to extend the size of display from 3.5 inch to 4 inch in next iPhone. These images also shows that iPhone 5 would feature a smaller home button compared to iPhone 4S. Previously, we have heard rumors about Apple to opt for nano-sim in next generation iPhone from a quite long time. 
There is actually no way for anyone to confirm about the authenticity of these leaked images. But we would assume that these are not fake, considering something similar we have heard in the past. Let’s know your thoughts about it in comment section.