Compute Environments can vary in size, anywhere from a few gigabytes to 40~50 gigabytes. Large compute environments can slow down execution start times significantly and of course consume more disk space on your docker image registry. It's valuable to understand how large the Compute Environment you've built is.
At the moment, however, there is no way to find the size of a Compute Environment from the Domino UI. If you need to understand the size of your image you must locate the image on your docker image registry
Domino Engineering is assessing the viability of adding the image size do the Domino UI.