from my experience with other vehicles, you can usually look at them and tell. they will be cracked and look like they are smushing out of where they should be. motor and tranny mounts are they same, google image or go put hands and eyes on a new one at the parts store then compare. any time ive had bad mounts they were visibly "distressed" we'll call it.
If an engine or trans mount is bad, you will notice a clunk when you take off fast.
The harder faster you take off from a stop, the bigger the clunk.
Clunks like that could also be due to other causes.
You usually can't tell by looking at them unless they're totally shot.