They're used as political catch phrases. However, it is possible to grow government and shrink government (in complexity). How you want to measure that is up to you though.
But that's really just things being done right issue, not a "size" issue.
They do mean something - not that the size of the government is different, but about what the parts are used for. In the 'small government' case, large portions of the State are operated by aristocrats as fiefdoms - this are misnamed 'private corporations'. In the 'big government' case, things are slightly less bad.
....and Torie still had the audacity to give us an article comparing California to a feudal society. Was that writer projecting?