Shift clicking on a tab (vertical or horizontal) should open a preview popup, with the contents of the page.
This acts a lot like the preview on tab hover, except it allows interaction with the web contents. The preview will reuse the web view from the tab itself, and only have a button to close the preview or open the tab its previewing.
Links clicked within that tab will act as if they were acted on within the tab itself; Clicking on links redirects the tab, opening a link in a new tab would open it relative to the tab being previewed.
An example use case might be checking your email for an online meeting code while not leaving the online meeting tab.
Checking or retrieving information from another tab without loss of context from the current tab.
