And finally (since he had started looking at the inadequacies of his life, why not make a comprehensive survey?) there was his recent weight gain; a full stone and a half, so that he not only felt fat and unfit, but was putting unnecessary additional strain on the prosthetic lower leg he was now resting on the brass bar beneath the table....... He returned to the bar to buy a third pint. Back at his table beneath the cupola, he drew out his mobile phone and called a friend in the Metropolitan Police whose friendship, though of only a few years’ duration, had been forged under exceptional conditions. (The Cuckoo’s Calling, by Robert Galbraith)
The chart that a grammar text has drawn says that ‘beneath’ is under a position, making contact with underneath of something; and ‘under’ is lower than that. But it seems not like that way when I look up Merriam-Webster’s examples below and the above example from Galbraith's story book. I rather say that 'under' and 'beneath' are used with the same meaning.
We had a picnic beneath a large tree.
We sat under a tree and rested a while.
the ground beneath [=underneath] her feet
I'm wearing a sweater under my jacket.
Does the chart deliver wrong message or was it making sense in the past - the text was written in 1967 ?