Sorry but I sadly have to disagree! Yes they may look cute and the little rider may well be having fun, especially if there are adults around saying how good she looks. But she is not balanced on the pony and is working so hard on him by kicking with her legs and 'driving' with her seat, she is travelling forwards in the saddle and even - it looks - is taking the saddle with her. She is literally driving the pony into the ground.
The sweet pony is doing its best but really needs to get away from that heavy surface to at least give him a chance to move - the flared nostrils are a give away as to the effort he is making, he is simply not fit enough to deal with the surface plus the weight of the saddle and his rider (who has pretty muh outgrown him already.)
The whole picture is one of great effort instead easy, pleasurable forward movement. Such a shame because with a few adjustments all round it could be so so different.
With apologies - just my opinion.
Anna