I have some vintage ad mirrors. They’re oval, have a picture and a company’s info on the ‘outside’ and a mirror on the ‘inside’.

Perhaps you need to re-write your first post !! Since you did not provide pics or additional info I normally assumed a reflective surface,, a mirror !!
These were also paperweights which is what you have !! Now why PJ Brown decided to use this design I can only guess !! One would assume that the pic of a beautiful lady would appeal to the man of the house who normally would choose a contractor if one was needed !! Men of that day and age rarely used pocket mirrors !! The paperweight would sit on the desk and keep the name in his view !! All needed to do was to turn the paperweight over for his location and other information !! Quite an innovative idea for that time !!

Now understand that we are simply volunteers here and are not employees of this site !! We have been in the business for many years and simply try to help with answers or research !! If you thought you would get anyone from this site,,guess again !!
We only use what you provide and in many cases that is very little !!