I liked your question, as I had spent time contemplating this previously also.
There would appear to be an inversion of the equations when describing them in words though. Thus for 2=9 I would say Stability is Change, rather than Change is Stability. The precedent for this being the readily established ones of the Supernals and of Tiphareth. As Jim mentioned the one for 5=6 is God is Man (Deus est Homo), rather than Man (5, the pentagram) is God (6, the hexagram).
The ones for the three Supernals are also well established, see Liber B vel Magi.
8=3 Sorrow is Joy
9=2 Change is Stability
10=1 Selflessness is Self
This just left me to figure out 4=7, which I got as Love (7, Venus) is the Law (4, the number of Law, as the fixation of Will, 2x2).
By reflection that gives us the following list:
1=10 Self is Selflessness
2=9 Stability is Change
3=8 Joy is Sorrow
4=7 Love is the Law
5=6 God is Man
6=5 Man is God
7=4 The Law is Love
8=3 Sorrow is Joy
9=2 Change is Stability
10=1 Selflessness is Self
To answer your question as to what is the difference between any two reflections, such as 5=6 and 6=5, Crowley writes:
"It should also be remarked that every grade has its peculiar magical formula. Thus, the formula of Abrahadabra concerns us, as men, principally because each of us represents the pentagram or microcosm; and our equilibration must therefore be with the hexagram or macrocosm. In other words, 5=6 is the formula of the Solar operation; but then 6=5 is the formula of the Martial operation, and this reversal of the figures implies a very different Work. In the former instance the problem was to dissolve the microcosm in the macrocosm; but this other problem is to separate a particular force from the macrocosm, just as a savage might hew out a flint axe from the deposits in a chalk cliff."
MTP Ch VII