I know this is a very old topic but I'm currently also leanring about the difference between classical and modern dressage and it's made me go out and find a classical instructor to begin lessons with!
I can not see the thrid photo at the moment (I'm at school and the computer blocks things so I can't see some files types) but both the first and second trot photos are disunited. Someone brought up an excellent point about JDI you not linging up on the same parts oft he legs, and each photo being in different stages of the trot. However, You can clearly SEE that the back of both horses is hollowed and the hinquarters are being left behind. There is great big flashy movement, with no engagment from behind!