If you, like me, sometimes feel silly bowing to the computer screen, the zafu, or the buddha:
So, joining our hands palm to palm, we simultaneously create and express the absolute, the oneness which goes beyond all dichotomies. It is from this perspective that we make the gassho, and that we bow.
It is no ordinary person who bows; it is the Three Treasures recognizing itself in all things. If anyone thinks of himself as "just ordinary", he is, in effect, defaming the Three Treasures. And as we place our palms together we unite wisdom and samadhi, knowledge and truth, enlightenment and delusion.
Dogen Zenji once said: "As long as there is true bowing, the Buddha Way will not deteriorate." In bowing, we totally pay respect to the all-pervading virtue of wisdom, which is the Buddha.
In making the bow, we should move neither hastily nor sluggishly but simply maintain a reverent mind and humble attitude. When we bow too fast, the bow is then too casual a thing; perhaps we are even hurrying to get it over and done with. This is frequently the result of a lack of reverence.
On the other hand, if our bow is too slow, then it becomes a rather pompous display; we may have gotten too attached to the feeling of bowing, or our own (real or imagined) gracefulness of movement. This is to have lost the humble attitude which a true bow requires.