Ok, I have just been into Yahoo emails, and made a Yahoo email account for myself.
I then hit COMPOSE and typed into the address box, my own default email address.
Subject line I just typed TEST
In the main text box, I looked to see how I could attach a picture from my pc in there.
At the bottom of the text box is an icon shaped like a paper clip.
I clicked on that.
Up came a drop down menu
re:
Share files from Google drive
Share files from Dropbox
Attach files from recent emails.
Attach files from computer
I clicked on the last one, and it took me straight into my files and I was able to select a picture from there and it just jumped into the email, and I clicked Send.
If your photos and pictures are NOT stored on your pc, then I suggest you try one of the "Fixes" I posted above....
Personally I would never keep my photos or pictures on a "cloud" or any other place, other than my pc.....as sometime in the future they are going to ask for money for doing this.......
Best of luck.....I did try.

Do please let us know how you got on.