Images not displaying, showing question mark or 'no image'

GP39 wrote: ? mark instead of pictures or it says "no image"

It's hard to tell from this. It would be helpful to know from this. Are you, in fact, running macOS 10.15 Catalina?

Can you tell us this:

1. Do you have more than one Photos Library?
2. Where does your Mac's Photos Library reside-- in the Pictures folder of your internal drive, or on an external drive? or on a network? on iCloud drive?
3. Are you using iCloud Photos to synchronize your devices? If so
4. …Do you have “Optimize Storage” checked in Photos’ Settings
5. …Do you see all your Mac’s Photos  pictures at iCloud.com?
6. …Have you checked to see if the Apple Account is really really the same on the Mac and at iCloud.com?
7. …What is your storage at iCloud.com? At System Settings>[name]>iCloud>Storage , my Mac says 176 GB of 200 GB used. What does yours say?
8. What is your storage on this Mac? At System Settings>General> Storage, my Mac says 745 GB of 1TBB used. What does yours say?

To narrow things down, try these troubleshooting steps:

• Restart the computer (of course)
• Re-start in Safe Mode. This bypasses certain potentially disruptive processes, and it often helps. Safe Mode is different for different computers, so see this: 

           Start up your Mac in safe mode - Apple Support 

• Use another library if you have one, or make a small test Library with a few pictures in it and see if the same thing happens. You can create a new Library by closing Photos and then option-clicking on the Photos icon.
• Make a new user and see if the same problem recurs with it.  This is a bit harder, because a new user can't access a different user's stuff. You would need to temporarily move your Library out of your own user's Pictures folder up to the general "Users" folder. 
• Rebuild your Photos Library--close Photos and re-launch by option-command-clicking the app icon. If you use iCloud Photos, it’s possible that this will cause a re-sync that lasts long enough to make you nervous. I usually turn off wifi when I do this.

The idea is to find out if the problem is with the Library, with your account, or with caches and login items, and stuff like that. One of these steps may fix the problem, but their failure to work also helps figure out what's happening.

Let us know what happens…

Do you use any optimizing or cleaning apps?

Do you use iCloud?

Do you have a managed or a referenced library?

Also, please make it clear whether you are talking about Photos or Safari.