V/T Question

Greetings everyone I am new to this list and IBIS, so I have a few
questions regarding model making.
One question is on extracting rising and falling waveforms. In the
cookbook (pg. 11) it says: "If the device does not have enough drive
capability to make a significant output transition then a higher value
of load resistance may be used,..."
I am unsure about the words "significant output transition". Does it
mean not reaching the Data Sheet Vol or Voh?

Thanks in advance,

Christian Klein