[Richard]

Yes to the first picture, no to the second. Just as Jon said.

I am going to post my opinion, it is just my opinion. I don't think a jack and cribbing is the same. When I speak of cribbing, I am talking about lumber, or solid steel such as an appropriately rated jack stand. My reasoning is that hydraulic jacks can fail. Or leak.

I almost lost a foot on this point when my youngest son misunderstood what I told him to do with the jack handle, and he released it. Lowering a 5000 lb car towards my foot. I flinched and the brake rotor hit the concrete where my foot was a second before. Freak situation, yes. My fault, yes. Jacks ain't cribbing.