What problems does that actually expose about his platform, or how does it show that his opponents are correct? It is barely even an ad-hominem attack - am attack on his character or reputation might lead me to believe that his viewpoint is held by untrustworthy people, but his face? It means nothing.
And yet it does have a small subconscious impact, causing a bias in my thinking.
Milliband was also mocked for looking silly when eating a bacon sandwich, but that was reframed as shallow media shenanigans.
Depends on the agenda, I guess.
http://i.dailymail.co.uk/i/pix/2014/10/21/1413910453638_Imag...
http://i.dailymail.co.uk/i/pix/2012/12/15/article-2248755-16...
http://i.dailymail.co.uk/i/pix/2016/10/02/01/39022CC20000057...
http://i.dailymail.co.uk/i/pix/2014/09/06/1409965807387_wps_...
In fact if you search on farage site:dailymail.co.uk vs farage site:theguardian.com it seems that, if anything, the latter tends to use fewer ridiculous images of him.
The Daily Mail also sometimes uses images of (left-wing) Jeremy Corbyn, such as this:
http://i.dailymail.co.uk/i/pix/2017/02/05/01/3CD6941A0000057...
http://i.dailymail.co.uk/i/pix/2016/05/15/00/33DD38440000057...
http://i.dailymail.co.uk/i/pix/2015/09/15/23/2C5822330000057...
http://i.dailymail.co.uk/i/pix/2016/06/09/18/351879870000057...
Sometimes it's bias and sometimes it's just poking fun at or ridiculing public figures, but it's everywhere. We're all biased.
https://www.google.co.uk/search?q=nigel+farage&tbm=isch
He's not exactly known for looking Churchillian.