Yes, you CAN, IF you FOLLOW directions the and do NOT use y edit the preferences in your YA activity profile, because THAT has not worked for YEARS.
How to change avatar
You have TWO PROFILES, and if you try to change your avatar in your YA activity profile, it is NOT going to work. You HAVE to go to your Yahoo profile first. To do that, on your computer,
Mobile devices MUST be desktop mode
1.Hover the cursor over or lightly touch whatever is to the left of the envelope icon near the upper right corner until "Account info " pops up, then left click or tap ":account info " to open your Yahoo profile. OR
2.Hover the cursor over or lightly touch the pinwheel /gear icon in the upper left corner until “account info” pops up, then left click or tap “account info”
3. If there is camera icon on the avatar is on or avatar icon, left click or tap the camera icon.. The My pictures folder or image gallery of your computer should open up..
4.Find the image you want to use as your avatar. left click or tap it to select it, then left click or tap "Open".
5.Center the image so it crop the way you want it to., then left click or tap whatever the butt underneath is labeled..
6..:Left click or tap the “Save” button
7. Then you need to go back to YA to your YA activity profile by left clicking or tapping your Yahoo nickname in the upper left column.
8. Then left click or tap "edit preferences,,
9.Left click or tap anywhere in the YA activity profile Refresh t the page, f5 key. you may have to open your YA activity profile. again. IF your avatar has changed in your YA activity profile, The NEXT step is very important.
10.Left click or tap Save" near the bottom. Yahoo's server computers are dumb, They will NOT apply or save new profile settings until you TELL the server computers to SAVE or apply the new profiles settings.
Given how glitchy YA has been , you may have to wait several days for your avatar to change.