Reproducing published extracts, images, figures, etc. in your PhD thesis

When your thesis is deposited in Spiral and made available to the public, legally it will be viewed as published and you must get permission to reproduce any extracts, images, figures, etc. for which you do not own the copyright (you can use works which are out of copyright without permission).

These are called third party copyright works.

Third party copyright

Types of third party copyright works

Extracts

Extracts include text or tables from books, journal articles, manuscripts, etc., and computer programs.

Seek permission to reproduce more than a short quotation from a literary work (as defined in the Copyright, Designs and Patents Act 1988 Section 3). 

You may be able to reproduce an extract under fair dealing exceptions but how much you may copy is not legally defined and you will need to judge for yourself how likely it is that the copyright holder would object to your actions. If in doubt seek permission.