Yes, in the example it looks like they are aligning the vertical stroke of the larger and small letterforms, but this isn't actually always the answer. The goal

Yes, in the example it looks like they are aligning the vertical stroke of the larger and small letterforms, but this isn't actually always the answer. The goal is to be optically aligned, rather than actually aligned and our brains' optics can really distort things based on size, weight, etc. If you zoom in about 300% you might notice that the larger text is actually still slightly indented, because the weight and size of it artificially occupy more space. Curves artificially create more space around them in our brains in relation to other letterforms and straight letterforms create less. As an example, type out the word "Highlands" in a very large point size (like 300pt) or in vectors where you can zoom in, in a well designed font. Drop a guideline at the baseline of the letters. You will notice that all of the flat-bottomed letters sit on a baseline and all of the curved strokes drop below the baseline. This makes them optically equal and appear to sit on the same baseline in our minds. The issue gets more complicated when you start using less geometric-looking fonts with serifs and higher contrast/different weight distributions in the characters. Even typefaces that look very simple and geometric, are still designed with subtle fluctuations in weight to make them feel optically even. Futura is a good example. The "O" character looks like a perfect circle, but if it were, it would look wrong. There is definitely some science behind all of this, but measuring and testing it seem like it would be very difficult.