Hello Tes and welcome to the forum with your question.
Zooming on your photo I’m seeing brood capping that the emerging bee chews to get out of the cell, it is dis-guarded by the colony and not used again.
If robbing was happening then with camera in hand you would have photographed World War Three happening at the entrance with dead bees on the landing board and under the hive. Heaps of buzzing, lots of bee to bee fighting with guard bees defending the hive. If you see it happening it is very obvious what is happening.
Relax Tes, what you have photographed is normal.
Cheers
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