Can you please confirm that Elastic Beanstalk is considered as a "container" type service as stated on the Shared Responsibility Model slide?
It is possible for the customer to install custom packages on EC2 instances, created by a Beanstalk environment, using ebextension. The EC2 instances are also accessible in the EC2 console, and one can SSH onto them. AWS provides high level platform configuration of the Beanstalk environments, but the customer sill has 100% access to the OS.
Here is the documentation I found: https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/platforms-shared-responsibility.html
AWS categorizes Elastic Beanstalk as part of the Container Services, with regards to the Shared Responsibility Model. This was mentioned in page 6 of the AWS Security Best Practices Whitepaper.