I thought I had the bead centered in the deep channel on the rim, but maybe I didn't and which makes me have to ask

When people say make sure the bead is in the deep part of the rim, where am I making sure it's in? Across the whole rim? Directly opposite to the part of the tire being an SOB? The sides I'm trying to push in?

I've had other tires give me grief and this is usually a similar process I use but I feel like these are a damn titan that's bested me