A.12 WCAG 2.1 Success Criterion 2.2.4 − Interruptions
Users must be provided with a function to turn off updates except in emergencies.
In this way, persons with attention deficit disorders can focus on the content without distraction. In addition, people using screen readers will not have content updated while they are listening thereby preventing confusion.
Before Rectification
If this promotion is an auto-rotating element, a user who has learning disabilities or low vision may not be able to read all the content before it automatically rotates.
After Rectification
The button allows a user to pause the rotation if required.
WCAG 2.1 Reference:
https://www.w3.org/WAI/WCAG21/Understanding/interruptions