Element of the Parthian Monument.
The Parthian monument is one of the most important monuments in Ephesus. It is located near Celsus Library. Some parts of the reliefs belonging to the Parthian Monument were found in their second location, placed on a later fountain in front of the Celsus Library. The reliefs show scenes from the wars of Marcus Aurelius and Lucius Verus against the Parthians. In addition to the originals displayed here the rest of the reliefs belonging to the monument are in the Ephesus Museum in Vienna.
1. (Replica) The scene of Hadrian’s adopted child Antoninus Pius adopting Lucius Verus and Marcus A|urelius. Front left is Antoninus Pius, on the right is Emperor Hadrian and in the middle the 8 years old Lucius Verus. Behind Antoninus Verus is 17 years old Marcus Aurelius and behind Hadrian is a male figure, probably representing Lucius Verus’ recently deceased father Aelius Verus.
2. Figure of an armoured soldier
3. (Replica) Figure of a woman holding Vexillum (Flag) representing the city Carrhae (Harran). From the Wikipedia: The Battle of Carrhae, fought in 53 BC near the town of Carrhae, was a major battle between the Parthian Empire and the Roman Republic. The Parthian Spahbod Surena decisively defeated a Roman invasion force led by Marcus Licinius Crassus. It was the first of many battles between the Roman and Persian empires, and one of the most crushing defeats in Roman history.
4. Selene and Appolon Helios (Moon and sun)
5 (large replica) Struggle of the Roman soldiers with Parthians.

This must be (part of) element 5