The agreement with Huawei is a symbol of the prosperity that comes from long-term partnerships, in this case a 20-year relationship with the Chinese business.
我在iPad上的回复老是被吞。 你的认识是正确的,这里确实可以当作同位语来看,之所以会让人觉得有点别扭,是因为没有直接引名词结构,而且前面也不是that is (to say), i.e., namely这样的结构。你把in this case放到最末端去,就比较明显了。然而,这里做补充说明其实更合适。