The leaves don't actually connect, there is a slit between them allowing you to see a grid when fancy graphics is enabled. (It is less noticeable in the photos, but when moving around in game there is intense shimmering between the surfaces.) It can still be seen close up on normal fancy leaves, but becomes more noticeable if you exam low detail leaves in the distance, or use a texture pack without see-through leaves. I checked the windows 10 edition and this is not a problem. Interestingly, while it is very annoying that jungle leaves can't be fancy on the mobile edition, they do not suffer from this issue.