This picture shows the two nebulae side-by-side just as they appear on the sky:
|Left: M8, the Lagoon Nebula. Right: M42, the Orion Nebula. North is up in both pictures.|
This next picture shows what they would look like if M42 was was at the distance of M8:
|M8 and M42 as they would be if they were the same distance away.|
As I mentioned in my last post, despite their differences M8 and M42 are more similar than not. Both are star-forming regions, both are large cavities of gas (mostly hydrogen and helium) and dust being blown open from the inside by young stars, both would probably appear boring and dark from the other side. The main differences are their size, as seen, and their location: M8 is situated nearly directly towards the galactic core from us, while M42 is located almost directly away. That's why there are a lot more stars visible around M8 than around M42.