Originally Posted by BenMcr

Most media polls are done in conjunction with polling companies, not as a poll on Twitter. Those polling companies usually try to have defined methodologies about how they select polling questions and who they ask.

For instance here's YouGov's page - https://yougov.co.uk/about/panel-methodology/ and here's Opinium's https://www.opinium.com/political-polling/

However the polling companies don't then control how the results are published in the media, and I would think that all media companies both left and right have some examples of where the summaries of the polls don't accurately reflect what was actually asked and answered.