Get a tissue, Valens!

I guess I should have some educational content here, too. Valentinian came to power after the mysterious death of Jovian, and he decided to share power with his brother Valens, giving him control of the eastern half of the empire. Valens would hold this position from 364-378 CE, when he was killed by the Goths in the disastrous Battle of Adrianople.

We don't know the contemporary name of this denomination, but modern writers usually referred to as a siliqua. It's often said to be worth 1/24th of a gold solidus, but that's based on the assumption that the ratio of the value of gold to silver was accurate in Diocletian's price control edict and that it didn't change during the fourth century. But there's plenty of examples of the relative values of gold and silver fluctuating in history, and there's no guarantee that Diocletian was basing his price ceilings on any more than tummy feels.

Regarding the imagery, imperial portraits started to become rather standardized in the latter 3rd century AD, with portraits more seeming to be of "the emperor" rather than the specific person on the throne. They're not necessarily always perfectly identical, but if you look at a typical coin of Constantine, Constantius II, or Theodosius, you'll see a guy who looks a hell of a lot like this. In the 4th century, the standard headgear of laurel wreaths or radiate crowns went away, and we start seeing diadems, this one likely representing one made of pearls. The figure on the reverse is again the emperor, and he's holding what's called a labarum, which is a military standard with Christian imagery. In his other hand, he's holding a globe, representing the world, and on top of that the personification of victory. The inscription around all that declares him the restorer of the republic. Roman coins were never subtle, and they only got less so in the 4th century.