Hi Mithilesh,
One possible reason for this issue could be that the images are not being loaded properly from the data source. Here are some steps you can try to resolve this issue:
Check if the images are being loaded properly from the data source. You can do this by checking the URL of the images in the data source and verifying if they are correct.
Check if there are any permission issues with the images. Make sure that the images are accessible to the users who are trying to view them.
Clear the cache of the app and try reloading the Gallery. You can do this by going to the File menu in Power Apps Studio and selecting App settings. Then, click on Advanced settings and select Clear cache.
Try republishing the app and see if that resolves the issue...
If none of the above steps work, please provide me with more details about the issue you are facing
