Why did impressionists wipe their faces?

[Dominic]

Years ago, I saw a guy doing some impressions on TV, and he would wipe his face with a handkerchief at the end of each impression.

I remember the presenter asked him about it, and there was a reason, possibly to do with suspicion or tradition. I cannot for the life of me remember what the reason was though.

So, my question is this, why does Danny Kaye wipe his face when he finishes his Louis Armstrong impression?

https://www.youtube.com/watch?v=t17cq8w5ewc

And stay watching for the scatting at the end.

[Dominic]

And to show you that he's not just blowing his nose, he does it here too.

https://www.youtube.com/watch?v=vnX2HxCiGb4

[josef k]

Because that is what Louis Armstrong did, and it would have to be included if it were to be an accurate impression.

[Dominic]

No, there was more to it than that. If you look at the second clip, he only wipes his face right at the end of the impression. I remember, in the interview I saw, the impressionist said it was supposed to represent them washing away face paint or something, to signify that the impression was over. I have tried looking for the clip, but I keep finding info on impressionist painters...