Bob wants to drive home a point about how important Alice is in two ways. The first way is that Alice is important to either a group of people or The Greater Good because of her knowledge, abilities, or some kind of emotional/spiritual role. The second way, which is usually where the weight of the scene lies, is that Alice is personally important to Bob on an emotional level, most often romantic but can be platonic as well. This scene could be a moment of realization for Bob as well.
Compare Anguished Declaration of Love
, which resolves or confirms UST
while We Need You...I Need You (very WIP title) may simply be an indication of deep affection, or even an affirmation between an already established couple.
Apologies if this falls under stock phrases, I know those aren't being added anymore. I've looked for this trope and haven't had any luck finding it.
Film - Animated
Film - Live Action
- Megamind. Roxanne Ritchie uses this on the title character.
Roxanne: Megamind, I don't even know if you are listening, but if you are, you can't give up. The Megamind I knew would never have run from a fight, even when he knew that he had absolutely no chance of winning. It was your best quality, and you need to be that guy right now. The city needs you, I need you.
Then once more in season 8, when Dean uses this in his I Know You Are In There Somewhere Fight with Castiel.
Dean: We're family. We need you. I need you.