that link is not the DBA view of LOB, it's just a developer summary (how big, pros, cons, ...)
for a DBA the primary points are, that 1) it can be big, 2) it is not directly inside the table
for 2) when you for example ALTER TABLE MOVE a table to another tablespace, the LOB still is where it was before. it is an own object
it doesn't mean that you can't SELECT MY_LOB_COLUMN FROM TABLE; of course you can do that.
but as DBA you have to remember that a table with a LOB column are physically 2 objects (the table and the LOB segement)