Yes, that’s a fixed wipe, we use on our templates wipes but wit different speeds and timing, with acceleration not fixed timing.
I’ve made a small video. In the first template we use a frame timer (Video Frame) and it’s visible that the video frame appears before the lottie. In real speed is more visible because etch frame you have 2 movements. On the second is with requestVideoFrameCallback and the 2 appear at the same time it appears like it was just one element. This is done in slow motion just to see the problem.
https://drive.google.com/file/d/1O8slH_F049BNuPpS--GJ788DcLlJWnRg/view?usp=sharing
With timers you can not sync video with other stuff.
Did not have the time to test requestAnimationFrame, can be a solution to this.