The happy parents wanted to honor the grandfather with the honor of reciting the brachos at the bris. They asked Rav Fried if the grandfather would be able to recite the brachos via Zoom or can they only give this honor to someone physically present at the bris? The mohel considered that because in Los Angeles at the time of the bris it would still be nighttime by the grandfather, the grandfather could not say the brachos - a bris cannot be done at night, so the brachos cant be said at night either. 

In general many poskim in the past have paskened that one cannot say brachos over zoom and fulfill people's obligations like that. The general psak, especially among Haredi posking, has normally been that this would not work.

Rav Amram Fried however paskened that because zeidy knows exactly when the bris is taking place, and the people present at the bris hear him saying the rbacha, zeidy can say the brachos from Los Angeles via Zoom, even though it is night there, and they will be yotzei with his bracha.

source: Hamechadesh