look at this
ASPolice's Channel - YouTube
she looks undecided as to whether she is going in.... she is perhaps wondering what to have for her tea, perhaps Waitrose did something that she liked but they didn't have it in stock so she went for her second option which was the Tesco pizza
It was said at the time that she was looking for a specific pizza but Waitrose was out of stock.
They have a witness between Waitrose and Tesco who Jo spoke to so I guess this is confirmed