[Dashboard subscription] Pivot table is not pivoted

[qnkhuat]

Describe the bug

If a dashboard subscription has a pivot table, sending it to slack will fail

To Reproduce

1. Setup slack
2. Create a dashboard
3. Add the "Orders according to sources per quarter" card from the example collection to the dashboard. It's a pivot table
4. Create a dashboard subscription to send to slack
5. Try sending it

Expected behavior

No response

Logs

No response

Information about your Metabase installation

master

Severity

P2

Additional context

No response

[qnkhuat]

you can send it now, but the rendered image is not "pivoted'
Pivot table on dashboard

Rendered image on slack

Rendered table on email