This is not a wise crack or sarcasm... the following is an attempt to explain what "open carry" is according to then Attorney General Granholm.
An excerpt from:
STATE OF MICHIGAN
JENNIFER M. GRANHOLM, ATTORNEY GENERAL
-snip-
Opinion No. 7113
-snip-
A plain reading of section 5o(1) of the Concealed Pistol Licensing Act discloses, however, that its prohibition applies only to the carrying of pistols that are "concealed."
A holstered pistol carried openly and in plain view is not "concealed" and therefore does not violate the prohibition contained in that section.
(Bold added for emphasis)
The entire Opinion can be viewed here:
http://www.ag.state.mi.us/opinion/datafiles/2000s/op10188.htm
My understanding of what then Attorney General Granholm said in that opinion is this....
A holstered pistol carried openly and in plain view................. is open carry. But that means the holstered gun and the holster both must be in plain view.
Hence a gun in a pocket inside pocket holster where a portion of the gun is concealed inside a holster that is concealed.... is concealed carry... NOT open carry.
Just because a portion of the gun can be seen doesn't mean that is open carry... open carry, per Granholm's opinion, is a pistol in a holster where holster and pistol are in plain sight.
In short... it would appear that Granholm defined open carry as a holstered pistol where holster and holstered pistol are in plain view. Conversely... if holstered pistol and holster are NOT in plain view... then it is "concealed carry".
Now an Attorney General's opinion isn't black letter law... but rest assured it will carry weight for the judge if a case comes to trial.
Or...... perhaps I'm reading that opinion incorrectly... although I suspect not... and someone more knowledgeable than I can chime in?