The Catacombs of Rome would suggest otherwise.
If I remember right early Christians took the prohibition against graven images very seriously. As a result the decorations in their churches ended up as intricate designs such as those shown here.
Yes, they called themselves Jews, and took to heart the fact that Moses saw no form of any kind the day the Lord spoke to him at Horeb out of the fire.
The Catacombs of Rome would suggest otherwise.
The images in the Catacombs were the first to come to my mind. There are also early images in the Christian tombs found in the excavation under St. Peter's Basilica, dating from about the same period.
The "Christ Helios" from the Scavi of St. Peter's:
The mosaic floors of the period would have been more prone to have designs on them simply because it would not be proper to walk upon a holy image. However, the Churches built contemporaneously to this Church that was just found would have had plenty of images - I would point you to the wonderful mosaics of the Churches of Ravenna for just a few examples.
One such image - Christ giving a crown of martyrdom to St. Vitale and a model of the Church of San Vitale to the bishop of Ravenna, from the apse of the church, finished about 550:
People who bring an agenda to the most casual discussion are really funny, in a “wake me up when they leave” sorta way.
“If I remember right early Christians took the prohibition against graven images very seriously. As a result the decorations in their churches ended up as intricate designs such as those shown here.”
I don’t know the answer to Chrisitan practice, but, assuming their practices came from Judaism (in contrast to Islam), a picture would be fine.
Only 3-diminsional icons would be a problem -— e.g., a statue, and then only ones of people or celestial bodies or the like.
Me, I would assume it was a design because it was a floor, and it’s a little creepy to walk on someone’s face.