Actually, Andromeda really is that big in the night sky. It’s wider than the moon in apparent size. It’s just that it’s very dim, so most of it is very hard to see. In good (i.e. very dark) conditions, it can be just barely made out as shown in the pic, though it’s not quite that dramatic.
And hey, give it a couple million years. It’s only going to get easier and easier to see.
The Large and Small Magellanic Clouds are also galaxies (visible in the southern hemisphere...or near the equator in the northern hemisphere). Named for Magellan, who must have been a bad guy, because (1) he was white and (2) he was killed by a non-white person.