- from a traditionally non-technical supplier and constantly changing supplier specs ( lumens is never capitalized unless beginning word in a sentence , as it is not named postumously after someone) so it is an error but not sure why. ( to err is human)
Here a similar bulb from same brand in a different country (Canada) is 8.5W 800 Lumens https://www.homedepot.ca/en/home/p.60w-equivalent-daylight-5000k-a19-dimmable-led-light-bulb-6-pack.1000835489.html Note they dropped the efficacy spec., possibly correct ! who knows. only your Test Engineer knows for sure.
If they started with emitters that were regulated to 7.5W with 106 lumens/Watt sources and had a design with 0.5W loss (14%) then it would use 8W with 100 lumens/Watt. The same bulb at 5000'K but with warm white might absorb 10% more energy to convert the blue source to warmer phosphor emissions and get only 95 lumens/Watt. Yet so many suppliers say they have the same efficacy for any CCT temperature from warm to cool. (Warning fake data)
Go to a reputable source like Philips, Cree, etc for better data,.
- luminous flux is the correct measurement for luminaires and LED components.
It is a weighted average of the Radiant Flux in the visible spectrum.
For what it's worth I have bought both warm and neutral white 5000'K in this brand from this suppier and the latter are awful white balance (poor CRI) and hideous so my wife insisted I change them in the hallway to warm white.
My preference is tri-phosphor 4500k 4ft T8 tubes or 4000~4500'K custom LEDs. But this range is also the hardest to control in phosphor thickness and std deviation or consistency vs cool and warm.