Depending upon where you are coming from, this could mark some progress, or not. I mean, if this horse was formerly very tense, short strided, head up, above the bit, or curled up behind the bit, then what you are showing would be some pleasant progress. Once he is more forward and more relaxed, you can add more contact and more impulsion from behind.
I would also not compare an arab to a warmblood. You will not likely ever see the same uphill pushing look in an arab as you'd see , like that photo. The arab has a flatter croup, by conformation, that means that he tends to have his back legs out behind him a bit more, and a bit harder to get that big reach underneath.
I like the look on your horse, and think you have a lot of potential. Your leg is further out in front of you than is optimal, and you can encourage more step under from him by putting yourself a bit more into the middle of the saddle seat, making sure your seat bones point straight down, that you do not put pressue back into the cantle, and maybe roll your pelvis forward a bit. It creates a bit more space under your butt for him to push up into.