Former product display engineer here. Many of those light bulb displays are only meant to demonstrate color temperature, and have completely different power systems on board then an actual light bulb. Usually the AC rectification will be removed and replaced with a DC/DC converter.
This is mostly so that the display can be battery powered, because the availability of AC power on shelf is pretty hit or miss. I wouldn’t trust a display to indicate if the bulb has flicker or not.
I had a similar issue when I applied after waiting for a year. The rep I talked too indicated that a ChexSystems report was the reason used by their "bank partner" to reject my application.
This sent me into a bit of a panic. There is absolutely no reason for me to have any negative reports in ChexSystems, and after pulling the report myself online, I found out there is no negative information at on the report. I relayed this information to the rep I was e-mailing asking if anything could be done, since clearly something had gone wrong. There was nothing he could do.
Five days after talking to the rep, I received a form from Simple in the mail for a ChexSystems report request. It was pre-filled with my name, birth date, current address, and social security number. Everything anyone needs to steal my identity in one convenient place.
I'm fed up with banks, but I'll take a bank over a place that can't open new accounts and mishandles customer information any day. I think it will be a lot less costly in the long run.
This is mostly so that the display can be battery powered, because the availability of AC power on shelf is pretty hit or miss. I wouldn’t trust a display to indicate if the bulb has flicker or not.