Nice video, well done. You seem very relaxed- impressive! I know I tend to lean into the push source somewhat, and this may be happening a little in your case too- if you notice how the letters in the sign across the street from your window, in line with the back of your head, are progressively revealed throughout the course of the video. It helps to have a mirror or something similar that you can check yourself against. Or maybe, like in the "Pushout" drill your partner can check whether or not you are leaning by abruptly removing his push and seeing if you fall forward or not.
We actually check ourselves like that. I guess you saw the vid for an example of us doing that:
We've gotten to a point where we don't push forward so much anymore. Yeah, we still lean. One of the major reasons is that we're working with a load coming in and we don't have all the structure just right. When the load/push comes in, something gives in our body, so we tend to adjust to that. Sometimes we adjust structure (the right way) and sometimes not (lean).
In my push test 02, I lean because I feel like the push coming in is pushing me backwards. I feel like the force isn't in the sole of my foot but moving me back towards my heel. So, in trying to get the feeling of the force in my sole, I lean. I'll eventually correct it with practice. But, it isn't a push back into uke kind of thing. If Brian were to remove his hand, I'd settle into my feet, but not fall forward. (As you'll see me do in push test 01.)
There is no resistance in aikido, so I must not resist or push back. It's why we do a check like you suggested every now and then. To show us that we're pushing back or if we're actually getting better structure.
Oh, the reason that I feel like I'm being pushed back? It's because my structure isn't just right. By that, I mean I should have the contradictory forces going, the intent down into the ground, the microcosmic orbit going, the intent down around the groin and up into the T-11, etc, etc. For me, what breaks down is my lower back tightening up and causing several intents to not work as they should. Once I relax my lower back, I am able to send the incoming force down into my legs.
I know it's working because my shins and calves scream. It used to be my quads. Then it slowly worked its way down to my knees. Now it's in my calves and shins. The only other place after that is the ground.
That's where it should be going in the first place if my body would cooperate.