A lot of times they will mount them to the wall if the unit is small enough. It’s cheaper and the refrigerant line run is shorter. But for larger units it’s common practice to mount them on a concrete pad on the ground. In this case, someone probably just didn’t want to spring for the wall mounting hardware, so they put it on a couple cinder blocks. It’s not ideal, but it doesn’t really hurt anything.
A lot of times they will mount them to the wall if the unit is small enough. It’s cheaper and the refrigerant line run is shorter. But for larger units it’s common practice to mount them on a concrete pad on the ground. In this case, someone probably just didn’t want to spring for the wall mounting hardware, so they put it on a couple cinder blocks. It’s not ideal, but it doesn’t really hurt anything.