In brief
The Early Christian monuments of Ravenna are an ensemble of eight buildings. The mosaic must connect to the specific space.
Useful to know
UNESCO includes eight early Christian monuments in Ravenna, built in the 5th and 6th centuries. Among them are basilicas, baptisteries, chapels and mausoleums, and mosaics are a leading part of their meaning. [1]
This variety is useful for architectural comparison of features without making an automatic ranking. Baptismal space and basilica are not the same, even if both have rich mosaic decoration.
When viewing a reproduction, first establish the name of the building and the place of the image in it. A detail from a vault should not be described as a stand-alone flat picture if its spatial position is essential.
A practical task is to connect three things: type of building, shape of space and place of decoration. This keeps the differences between the monuments, instead of all the images from Ravenna becoming one common imaginary interior.
Sources
For further detail and to check the information: