Books that have off-consensus lines late

[Bullajami]

This may not be the correct forum for this question, so if it needs moving - move it.

I have noticed that a few bookmakers will adjust some of their lines in the last hour or two before game time to be outside of the general consensus range. I also notice this seems to happen on games with a more popular/public team playing.

For example, most books will be offering
-180 Public Team
+165 Mudville

and suddenly a book (usually a smallish book) will move their line to
-200 Public Team
+180 Mudville

Is this book attempting to exploit the public bias in order to be more profitable
or
Are they trying to generate additional action on Mudville to lower their exposure on this line

Again, this is specific to when it happens close to game time.

While it does not really matter (to me) what the motivation is, I am curious. (And maybe it should matter to me, and I don't yet know why.)

Thanks.

[Munson15]

SIA does this all the time in most sports, I would think to level off their action and draw some bets to the dog.