L for Lens Distortion
The lens refract light and hence certain amount of distortion is introduced. It might be in terms of picture quality, or changes in shape. Common are, barrel distortion and vignetting.
Barrel Distortion is where the photos bulge near the mid of the frame. Its pretty common, but less noticeable in the fixed focus lens.
Vignetting, is when the edges of the photo become dark. In some cases, it adds a bit of drama but, it is still a lens issue.
Often, these are corrected by introducing appropriate lens information corrections during post processing.
Viewing full-screen helps 🙂