The lighting isn't great so it's hard to see details, but nothing pops out as being a "THIS is definitely causing your issue" type deal. You're a little high and you move your head around instead of keeping it still and gaze down, which could both be improved, but nothing obviously causing severe hip flexor pain. You may be using your hip flexor eccentrically to "brake" and keep yourself above parallel, but that's kind of a shot in the dark.