eggshell said it well. Can't be certain without being there, but if I think there's any way at all to either get closer or to a better spot, I'm moving. Sometimes that means just moving over one tree, and other times it's a mile walk in a circle around the bird.
A week or so ago on a property I hadn't hunted in twelve years a turkey gobbled about 150 yards behind me while I was standing up glassing a big field. I moved back about ten yards and sat down against a tree and hit the call. He cut me off and a moment later he gobbled on his own less than a hundred yards away. About then I realized I'd screwed up and remembered there was a pretty big ditch that would probably stop him forty yards from me.
There was a small ridge and thick woods between us, and I made a quick 25 yard move. He gobbled at the leaves when I started the move, but never made a sound after I sat down. I waited a minute and scratched leaves...nothing. Called soft...nothing. Waited...nothing. I decided I'd bumped him as he was coming fast and must've topped the ridge before I got set, but I'd give it ten minutes. Soon I heard drumming and in walked three gobblers. I dropped one and waited for the others to finally wander off before picking him up and walking to the truck.
That move was a big risk in regards to possibly bumping the bird, but I'd rather bump one by pushing than watch/listen to one strut around just out of range.