Spotify iframe API play()/resume() starts preview playback while iframe controls allow full playback

[j4n0nym0u5]

I am seeing different behavior between playback started through the Spotify iframe API and playback started through the embedded player’s own controls.

Environment:
- Spotify Premium account
- Logged into Spotify in the same browser
- Desktop browser
- Spotify iframe API
- Music track and album embeds affected

Steps to reproduce:
1. Load the Spotify iframe API.
2. Create an embed controller for a track or album URI.
3. Call EmbedController.resume() or EmbedController.play() after a user click.
4. Playback starts as a preview.
5. Use the embedded Spotify player’s own controls inside the iframe.
6. The same embed can then play the full track/album, including skips and normal player controls.

Expected:
For a logged-in Premium user, EmbedController.play() / resume() should start the same full playback mode that is available through the iframe’s own controls.

Actual:
The API-controlled playback path starts preview-style playback, while the iframe’s internal Spotify controls allow full playback for the same user/session.

Question:
Is this intended behavior, or is this a bug in the iframe API playback path?