1. When uploading a video, remember to click add Video, not Image.

2. After uploading a video, you can change the thumbnail, the image of the video that is showed in the post. Tap the uploaded video and click "Change thumbnail".

3. Click here.

4. Then 6 photos from the video will be suggested. Select which of the images you want to use as a thumbnail at the beginning of the video.

5. If you don't like any of the 6 suggested photos from the video, you can upload a custom thumbnail.