it's very nice, I have had two examples from Theodosius I, but none from Valentinian II.
Dumbarton Oaks dates this issue to A.D. 385 because of the consular dress.
I know that Valentinian II was consul in 387, Theodosius in 388 and his son in 385. But the commemoration of the consulate of the latter is not convincing for me.
RIC said that this emission could celebrate the consulate of Theodosius and for me this is more probable. I think that this is an issue to put in the years 387-388, when Valentinian fled from Italy to Thessalonica (Theodosius residence in those years) because the invasion of the usurper Maximus.
In 388 we have Maximus as consul in West (sine collega?) and Theodosius and Maternus Cynegius in East, so at least three consul in a year, none of them suffectus. It is probable that Valentinianus has not recognized Maximus as consul in West, appointing Theodosius as consul (Valentinian was the senior augustus, despite his age, so it is likely) with Maternus (friend of Theodosius, maybe on suggestion of Theodosius himself).
So this issue may have vehiculated the message of Valentinianus "I'm still the legitimate emperor of the West and, as such, only me can appoint a consul. I don't recognize you, so I appoint Theodosius (and Cynegius)".
The presence of the staurogram over the campgate, not present in the previous issues of the same type, also, may put this issue in the year 388, because it is the same symbol that we find in the successive emissions of 388-392 for Theodosius.
But mine are only hypotheses.