This form builds directly from where Short Form 1 started and left off. You are doing the same movement of Short Form 1 with an addition. In this case, the addition is a punch. (But you know that that is not enough for a long form.) The second half of this form is also Short Form 1, just on the opposite side, with two additional blocks added to it for every step of the way.
Throughout the first section of Long Form 1, you will shift into a forward bow stance (heel down!) on the reverse punches, which are all done at shoulder or solar plexus height. In Long Form 1, we lock into the forward bow stance for form and definition of that power, yet in later forms and in all techniques, the forward bow is only transitory. As in Short Form 1, the elbow returns can also be regarded as rear elbow strike or elbow block like Star Block Set, and all direction changes are accomplished with an inward block, as well as the primary block.
Short Form 1 is essentially there to teach you to step back and establish your base with a block. If you can't block, you are in serious trouble. With Long Form 1, we are still stepping back to gain that base and then counter with the forward bow and the punch. The idea behind this is that you can't win a fight by simply blocking.
The first thing one notices as quite different is the cat stance used as the second step. It's purpose is to show you how to do a proper step-through in reverse from a forward bow. When people try to do this without training, they raise up, which is not beneficial to you maintaining a good base.
The next thing people notice is the elbow added prior to the initial upward block. It can be broken down into a series of moves. As you cover step, your left punch is out. Pivot into a horse stance as you execute the outward elbow. Then you have to the upward block, which requires the chamber and block as you complete your pivot into a neutral bow and facing your attacker.
The third area people notice is the initial downward block. There are multiple reasons we step in to our attacker here. In Long Form 1 we block and counter attack, correct? Therefore we are moving in to position ourselves closer to initiate a reverse punch. In addition to this, most martial arts tell you to "Never step into darkness" for self-defense reasons. In Short Form 1 after the second upward block, look to your right. You can't see much but your right arm. This means to step away as you can't see what is coming. In Long Form 1, we have thrown a punch and chambered out right arm. With the right arm chambered, we can see what's coming and we can determine how to react. In this case, we choose to step in. In Short Form 2, our hands are cocked at our side, we can see what's coming so we step in. In Long Form 2, our hand is up following the back knuckle so we cannot see what is coming. We have to step away and block.
The next section of Long Form 1 consists of the left side of Short Form 1 with additional blocks. The rotation you use on this part of the form should have no lower body rotation. The upper body has to rotate for the block to cover your entire body, but a forward bow on your lower body is not needed to accomplish this.
The final section of Long Form 1 is the isolation. The purpose of an isolation is to give a preview of what's to come and category completion. In this isolation, we are previewing what's to come for both Short Form 2 and Long Form 2. The blocks are also blocks not normally used in the usual string of techniques that have been learned. Intellectual Departure uses the inward downward block palm down and Raining Claw can be said to use the inward downward block palm up. The push downs are used more as checks in our system than actual strikes to stop knees. (You can't stop a real rising knee with a push down like that, your arm will buckle. You would have to pivot and turn your arm so your fingers point towards you-- this way the body will move and the arm shouldn't buckle.) These strikes are shown in action in Long Form 2. The blocks also act as reverses of previously done blocks or as blocks on a different plane of motion.
The punches that follow are there to simply point to angles, straight forward, at the angles, and to the sides. Since they aren't strikes in the sense of a self-defense technique you are not supposed to pivot into full forward bows like you want to; just the upper portion of your body should turn.