predicate offload

If a predicate offload (“cell physical IO bytes eligible for predicate offload”) is more than "physical read total bytes", does this mean its due to smart scan?

Other way round, if physical reads are more than predicate offload statistics, which 2 might be the reasons listed below to be the cause?

1) IOT table

2) index clustered table

3) uncommited transaction causing changed blocks

4) migrated rows on the table