What is the effect of an annexation on a property?

In Haggert v. Brampton (1897), S.C.R. 174 at 182, King J. commented on the object of annexation: In passing upon the object of the annexation, the purposes to which the premises are applied may be regarded; and if the object of setting up the articles is to enhance the value of the premises or improve its usefulness for the purposes for which it is used, and if they are affixed to the freehold even in a slight way, but such as is appropriate to the use of the articles, and showing an intention not of occasional but of permanent affixing, then, both as to the degree of annexation and as to the object of it, it may very well be concluded that the articles are become part of the realty, at least in questions as between mortgagor and mortgagee.