This article seems to be vague about what 'one shot' means. The closest it gets is 'one video', but one video might contain many examples. In the first case - put the peach into the red bowl - one example is not enough to distinguish this from, for example, put it in the most distant container. If the demonstration contained only one example, then it is unclear to me how strongly, and how specifically, the meta-training needed to pre-condition the system in order for it to pick the 'correct' interpretation of the actions in the demonstration.