A Salesforce Object could be linked to multiple Jira issues through a variety of ways:

Viewing related Jira Issues in a Salesforce Object page

To assist in keeping track of all these issues, a window in the Salesforce object page layout can be configured by a Salesforce administrator to display the linked issues.

Refer: Configuring the "Related Jira Issues" View with the Fetch Endpoint

This window could be placed anywhere on an object page layout but looks similar to below:

The issues are links which can be clicked to open the issue up in Jira. The link will open inside a new window.

A note regarding newer browsers

There is an issue regarding newer browsers which may render the Related Jira Issues panel blank.

If you encounter this problem, consult this Knowledge Base article: Related Jira Issues May Appear Blank.