The similarity between the two Industrial Revolutions is that they both involved an increase in the degree to which machines were being used to do tasks that had once been done in other ways. Yes, there were differences in that the earlier Industrial Revolution was more about things capital goods like steam engines while the second was about consumer goods. But, in both cases, the main thing that was going on was an increase in the use of machinery. This is what they have in common and what makes it legitimate to call both of these "Industrial Revolutions."
