That red cloth is a "fukusa"; it is a vital tool used to cleanse the tea equipment.
I would like to draw your attention to the fact that Kanjisho uses multiple sources of data provided by third parties.
The search results are provided by the wonderful Jisho API which itself uses various data sources which you can find on the jisho's website. The data concerning the kanji strokes are provided by the KanjiVG project, under the CC BY 3.0 FR license. I also use Tatoeba to provide example sentences and Kuroshiro to obtain the furiganas and romajis versions of the sentences.
If you find any vices, errors or malfunctions, please let me know so that I can correct them.