You are correct in assuming leg lift. This is a quote from Steven Ellis Leg Lift
"The first stage of the pitching motion is the leg lift. The leg lift occurs when the pitcher pivots the throwing foot on the pitching rubber to perpendicular to home plate and raises the glove foot. The leg lift is important for two different reasons. First, it starts the pitcher’s momentum toward the plate. Momentum is important for the pitcher because it helps generate force behind the ball. Secondly, the leg lift allows the pitcher to load the back leg and hips. The pitching leg is loaded when the glove foot leaves the ground. When the pitching leg is loaded, there should be a slight bend at the knee. The pitcher’s eyes and head should be focused directly on the target. On the lift, the pitcher’s glove should line up with the knee and serve as a good indicator for the height of the lift. Many times, our pitcher’s gloves will be at letter height on their uniform. Also, the pitcher’s chin should line up with the knee and glove. Lining up the chin, knee, and glove indicates good posture that promotes a controlled balance.
There are many different styles of leg lifts practiced by major league pitchers. Nolan Ryan practiced a very high leg lift. He attributes some of his throwing velocity to the high lift. When analyzing a high leg lift compared to a conservative one, it seems that pitcher’s that get their legs higher have extremely good flexibility. Also, it seems that their weight thrust back to some extent toward second base. Thrusting back toward second, at least in Ryan’s case, seems to create extreme momentum toward the plate. To further illustrate my point, let me provide an example. Visualize a four-legged table. Now, imagine two legs on the same side being cut. The table would fall until the new leg height contacted with the floor. The higher the table legs are cut, the further the table will fall to the floor. By adding extra distance, the table will come down with more force due to increased momentum from gravity having more time to pull on the table’s falling mass.
But, pitchers should be aware that practicing a leg kick that is too high or out of control can severely hamper their pitch command and keeping all applied force in a straight line. The kick should allow be at a level that the pitcher can continue to maintain their balance throughout the delivery."
So in essence, I believe they are saying you have a nice leg kick that allows you to lead or load with your hips down the mound. My guess is that you may have a slight pause at the top of your leg kick. It is hard to get a true read into what people really mean with just words but if everything is working well for you, I wouldn’t be concerned. Hope this helps,