Delay while rendering images on HoloLens

Question

I developed an Unity app on the HoloLens Gen.1. The app renders images which are received via HTTP according to the principle of Motion Jpeg.

The "problem" I have is that the "video" has a delay of 3 Sec. to the original source.

Can somebody explan to me how it comes. Then I use the emulator there is almost no delay.

Thanks