Hey there, Amalalobidli.
It looks like your iPhone is having issues downloading the full resolution version of a photo (or photos) from iCloud Photos. If you haven't yet, you'll want to ensure that your iPhone is connected to a strong reliable internet network, or try another internet network. Trying multiple can help isolate if the issue is happening with multiple internet networks or only one.
You'll also want to make sure that Low Power Mode is temporarily turned off while trying to download photos from iCloud Photos, as Low Power Mode can affect iCloud Photos: Use Low Power Mode to save battery life on your iPhone or iPad
If we've misunderstood the issue, please let us know more details to help us understand better. Also, let us know if those steps help.
Take care!