There are multiple reasons why using images of code, error, logs and other text resources used in programming instead of the actual text is strongly discouraged.
Shortly put, the question should be written in a form that helps both the fellow community members to answer it (e.g. easy to copy-paste the code to provide an answer) and the future readers (e.g. read and copy-paste the code).
Reasons to paste text instead of images:
hard to get the text - it is harder to get the text from an image than a direct copy-paste. This means wasted time for a person who want to answer it due to extra effort involved in retyping the provided code
harder to read - most of the images will be shrunk to fit the post maximum width, will be unreadable and thus force the reader to open it separately to view it full width
non-searchability - site search or search engine will not get to the text inside the image
non-accessibility - screen readers need to be way smarter to get the text from an image, so it will make life harder for those with visual impairments
hides formatting, whitespace, or incorrect characters - prevents the readers from fully understanding some possible errors caused by incorrect indentation, non-visible characters or Unicode characters that look identical to the ANSI ones
Note: This post was inspired by a very similar SO one.