A samurai uses a toothpick even when he hasn't eaten.

Literal

Samurai [topic-は] eat-not-even-though high-toothpick.

A classic Japanese proverb meaning 'keep up appearances even in hardship.' 食わねど uses the classical negative ~ぬ in its concessive form ~ねど ('even though not'). 高楊枝 (picking teeth after a meal) symbolizes the pretense of having eaten well. The structure is compressed and archaic.