Video appearing small



I uploaded a video (mp4. format) that appears quite large when I play it in Quicktime on my computer, but when I scan the Zappar code with it embedded, it appears very tiny, like a thumbnail in the centre of my phone’s screen. Do you know why it is not taking advantage of the whole screen? The aspect ratio is the same. Something must have happened during the upload and Zappifying progress that made it small.

Thank you,