We just recently completed Lightning training for our Customer Service team and they had follow up questions around escalations. In the views in Classic, there was a red arrow indicating that the case was escalated. In the views in Lightning, there is not an indicator for this which makes it more difficult to prioritize. Please vote for the attached idea if you are also in need of this functionality.

https://success.salesforce.com/ideaView?id=0873A0000003XUtQAM