Your trainer can attach a video to any exercise in your program. Depending on what they attached, the video shows up in one of two ways inside the exercise info tab.
Uploaded videos play in the app
If your trainer uploaded a video file — a demo they recorded themselves, or one of their coaching cues — it plays inside the exercise info tab. Tap the play card, the trainer's clip starts. It plays through once, at the natural aspect ratio your trainer recorded, and has sound (unlike the muted library clips).
A trainer upload replaces the standard library video in that slot for that exercise.
YouTube and other links open with a "Watch video" button
If your trainer attached a link to a video — a YouTube URL, a Vimeo link, anything hosted elsewhere — the exercise info tab keeps showing the standard library video, and adds a Watch video button below it. Tap the button; the link opens in the appropriate app (YouTube in the YouTube app, other URLs in your browser).
External links don't replace the built-in demos: you get both.
Trainer notes
Below the video area, if your trainer added a written note, you'll see it labelled Trainer note. It appears when the trainer's video is the primary content — always for uploads, and for links only when there's no standard library video for that exercise.
When new videos appear
Videos your trainer adds appear after your trainer sends or updates your program.