Complex sentence: On the other hand, from the point of view of the ladder, it is the garage which is moving, and is therefore length contracted, and will need to be larger than the rest length of the ladder in order to contain it.
Split into simpler sentences: On the other hand, from the point of view of the ladder, it is the garage which is moving and its length will contract. The garage will therefore need to be larger than the length at rest of the ladder in order to contain it.