I will leave it to experts on the iconography of Canaanite gods to take positions on whether this stone fragment is a relief representation of one of them. At minimum I would like to see some complete parallel stone reliefs.
There is no reason in principle why a Yahwistic temple in the Iron Age could not have included representations of other gods. According to the Deuteronomistic Historian, King Manasseh of Judah put altars to other gods in the Jerusalem Temple (2 Kings 21:4-5). Of course, Dtr disapproved, but still acknowleged it happened.
For PaleoJudaica post on the Iron-Age temple at Tel Moza (Tel Motza, Tel Moẓa, Tel Moẓah), see here and links.
Visit PaleoJudaica daily for the latest news on ancient Judaism and the biblical world.