line 19 column 1 - Warning: <img> lacks "alt" attribute
line 23 column 41 - Warning: <img> lacks "alt" attribute
line 25 column 38 - Warning: <img> lacks "alt" attribute
line 26 column 1 - Warning: <img> lacks "alt" attribute
line 26 column 20 - Warning: <img> lacks "alt" attribute
line 26 column 39 - Warning: <img> lacks "alt" attribute
Info: Document content looks like HTML5
Tidy found 6 warnings and 0 errors!

The alt attribute should be used to give a short description
of an image; longer descriptions should be given with the
longdesc attribute which takes a URL linked to the description.
These measures are needed for people using non-graphical browsers.

For further advice on how to make your pages accessible
see https://www.w3.org/WAI/GL.
About HTML Tidy: https://github.com/htacg/tidy-html5
Bug reports and comments: https://github.com/htacg/tidy-html5/issues
Official mailing list: https://lists.w3.org/Archives/Public/public-htacg/
Latest HTML specification: https://html.spec.whatwg.org/multipage/
Validate your HTML documents: https://validator.w3.org/nu/
Lobby your company to join the W3C: https://www.w3.org/Consortium

Do you speak a language other than English, or a different variant of 
English? Consider helping us to localize HTML Tidy. For details please see 
https://github.com/htacg/tidy-html5/blob/master/README/LOCALIZE.md