Shop as Customer allows a store Administrator or Shop Manager to shop the front-end of the store as another User, allowing all functionality such as plugins that only work on the product or cart pages and not the Admin Order page, to function normally as if they were that Customer.
Once installed, the Administrator can easily switch to another user with 2 clicks, then shop the store as that user would see it, with all functionality and plugins that would only be visible to that user, working perfectly.
Such as those that work with User roles, inputting custom variables (meta) on product order that are not supported in the Admin Orders screen, etc. This enables incredibly quick and simple manual order creation. And with another click, they can switch back to the Administrator or Shop Manager.
Once a cart is created for a User while shopping as them, instead of seeing only the pay button on the checkout page, the Administrator or Shop Manager now has convenient buttons to also email the invoice directly to that User for payment or link to the Order created in the Admin section.