  Strong converse theorems refer to the study of impossibility results in
information theory. In particular, Mosonyi and Ogawa established a one-shot
strong converse bound for quantum hypothesis testing [Comm. Math. Phys, 334(3),
2014], which servers as a primitive tool for establishing a variety of tight
strong converse theorems in quantum information theory. In this short note, we
demonstrate an alternative one-line proof for this bound via the variational
expression of measured R\'enyi divergences [Lett. Math. Phys, 107(12), 2017].
Then, we show that the variational expression is a direct consequence of
H\"older's inequality.
