Irrelevant. We're talking about the digital movie contained on the DVD, not the physical DVD itself.
It's not irrelevant. You never mentioned that the friend was ingesting this in any way other than taking a physical disc from you. You've moved the goalposts and pretended that you scored.
If we're talking about the digital movie contained on the DVD then you don't need to lend your friend the DVD. You can just rip it and send it to them and that is theft because you've made a copy of the content without paying the creator of that content. The entire distinction is whether you're lending (which itself implies a temporal nature to the idea and a physical limit) or a duplication of someone else's effort without compensating them for that.
Explain how 3 is stealing and 2 is not.
I already have. One is physically limited, the other is not. One is created with the physical, temporal, and material limitations inherent to it while the other is not. If your friend has your DVD, you can't watch it while they have it in their possession. Something being intangible doesn't mean it's not worth compensation.