Poll Units may be used in two different ways.
The first instance has two subtypes.
In-article
First, it may be placed in an article with a width of 500px or more. It will look something like this:

Here is an example.
Sidebar
The second subtype is a right-rail or sidebar placement. Sidebar widgets look something like this:

An example may be seen here. You may read about the standard implementation here.
Polling hubs
The second type of deployment is a polling hub (formerly known as a carousel). The questions are shown with a preview of the following question to the right, and a reminder of the last question answered to the left. The dots above the question text indicate the polling session's status as the user progresses through the experience.

A polling hub example is shown here. Information about the integration may be found here.
This implementation is typically used in a polling hub where the page's focus is the polling experience. Polling hubs are a great way to increase time spent on your site and, therefore, ad revenue.