Apparently if you serve a glass of beer, it should have froth. I remember pouring my first glass of beer for dad. He was not very happy. I just emptied the beer into the glass, and he got froth, it was almost all froth and no beer.
I the had my first lesson on how to pour beer into a glass, english metho, from dad. You hold the glass on a slant, and as the beer enters from the bottle you gradually straighten the glass. This produces the perfect glass of beer: a third of bubbly froth and the rest beer.
My washing machine sometimes complains that there is too much froth. It is unpredictable, but sometimes I get a warning that the wash programme will take more time due to froth development, which means when I go down to my laundry room in the cellar the programme still has half an hour to run.
And then there is the froth development which mainly occurs amongst politicians, comparable again with a washing machine, the programme for delicate material. If you watch through the window of the machine, you see a basis of water at the bottom supporting a window of froth, bubbles. This often occurs when a political speech is being held. There is a small amount of words used to express the problem. but let us be honest, the rest is froth, air filled bubbles with nothing really worthwhile to listen to.