Although he was a son, he learned obedience through what he suffered. (Hebrews 5:8 )
A Miaphysite christology would say that God the Word learned obedience through what He suffered in His humanity. Or, more directly, One of the Trinity learned obedience through what He suffered, in His humanity.
For it was fitting that he, for whom and by whom all things exist, in bringing many sons to glory, should make the founder of their salvation perfect through suffering. (Hebrews 2:10)
Same principle, human actions are done by God the Word, in and through His humanity.
A Leonian christology (named after St. Leo of Rome) would say that the one Lord did these things in His human nature, in connection with the Divine Nature, following the principle he layed down in his dictum: For each form does what is proper to it with the co-operation of the other; that is the Word performing what appertains to the Word, and the flesh carrying out what appertains to the flesh. One of them sparkles with miracles, the other succumbs to injuries.
The emphasis of a Miaphysite is on the Person of God acting, excluding the possibility of two subjects of attribution (two natures). There is only one composite
nature of God the Word. The word composite indicating that there is no mingling of natures, both remain intact as to their properties, but for all practical purposes they can no longer be dealt with separately (unless in abstraction). The Leonian emphasis is upon the real distinctiveness of the natures in their properties and actions. The Word doing the divine things and the human nature the human things. There are two subjects of attribution
for St. Leo but not
[/b] two persons. The two subjects of attribution exist in One Person (Persona which St. Leo equates with Hypostasis, not
The difference between the two, even though you did not ask, but perhaps another reader will benefit, is one of emphasis. There is no dogmatic conflict.