Peter Barkworth, in his book "About Acting", says that this little snippet of technique was given to him by Evelyn Varden, an American actress who died some years ago, but was a big hit in Lesley Storm's play, "Roar like a dove", that enjoyed a three year run at the Phoenix Theatre.
Here is an example of 'talking off'.
You are looking round a room and remarking on various ornaments and pieces of furniture. Once you have seen an object you can turn away from it while talking about it, so that your eye can alight more readily on the next subject to which you are going to refer.
Evelyn's part was Muriel, an American matriarch, visiting her daughter who is married to a Scottish Earl. On her first entrance she looked around the library, inspecting it. Her speech went:....
"the lamps are new.... and those drapes....(she wanders up to the yellow curtains, touches them). Very nice....but in America we got over that yellow craze years ago....(she glances at a small table). Gracious - where's the snuffbox that belonged to Prince Charlie?"
Now, having looked at the lamps, she turned "off" and looked towards the curtains while saying, "The lamps are new", so that she could say almost immediately, "and those drapes". She used the line, "but in America we got over the yellow craze years ago" to look towards the small table.

Peter Barkworth says this device is very useful, for it is extremely natural, and it helps you to get a move on.