All of the photos on the show are ones that I have taken myself. (If you want to know where they were taken, please email me: thedailyenglishshow.blogspot.com). I have shown the photos for their educational value. Checking the errors in your own or someone elses work is a useful study method.
If you are interested in the entertainment value of English mistakes, see Engrish.com. That site focuses on the humour of the mistakes, and mainly includes mistakes found in the English used in Japan for design purposes (t-shirts etc).
I think if the English is used for design only, it’s not too important if it is correct or not. However, if it is for a sign or menu it is important to check it carefully before it is printed.