I'm not really sure Flower is the smartest lynch here. Any form of tanking kill or lynches on a Survivor is gorssly overpowered, because it basically guaratees a win unless one, or multiple, factions decide to dedicate significant resources just to remove the Survivor from the game. So given this, I really don't think Flower is a Survivor. At the same time, I do believe they have some form of lynch immunity, because Day 1 is the Day Town are most likely to test that out. Given this, I'm left with a few possibilities -
1 - The Flower voters want to test Flower's claims, and genuinely suspect them.
Fairly likely, but somewhat wasteful too. There should be enough resources in this game to circumvent "Deathproof" abilities, so I'm not sure we need to burn a lynch to test it. And regardless of the answer, it doesn't really change how we plan to resolve Flower.
2 - The Flower voters are scum with Flower, and are burning the Town lynches on an unkillable scum member.
A cursory look over a recent game tells me Flower did exactly this with a scum team recently, and it does make some degree of sense all told. From a psychology standpoint, if Town are committed to lynching Flower, then things like discussion are vacuumed until Flower is dealt with, which provides a significant advantage to scum. And plus, getting the Town to waste lynches is always good. The drawback to this is that unless Flower's lynchproof indeed is time-based rather than X-Shot based, it would be more powerful late game than early game, and so to use it this early would be somewhat wasteful for Scum. But, I could see this being a valid possibility.
3 - The Flower voters are not allied with Flower, but one of the other wagons are scum, and players are attempting to save them.
This is somewhat of a stretch, because the current counter wagons to Flower are just myself and Usopp, and more importantly, the votes on each of us are about two. I think Fuji may be around there too now, but in any case, the point remains. Instead of dumping a lynch onto Flower, scum could pretty easily offer a viable extra wagon even in the time we have left, and failing that, could pile on just one or two votes onto another counter wagon that has an almost guaranteed chance of going through and not have to be obvious about saving a scum buddy at all. That being said, it is a possibility still. I obviously know what my role is, but should Usopp flip scum, I would be giving a second look at the Flower votes. But, frankly, it's a weak argument, and out of all the possibilities I've suggested here, this seems like the least plausible to me. There are just so many better ways to handle it than dumping votes into Flower, especially because if the lynch does in fact fail, they'll be drawing some attention to themselves anyway. And if Flower is indeed not scum, but some kind of Serial, then said Flower voters are risking retaliation from Flower.
These probably aren't all the possibilities that are in play, but the first ones that came to mind for me. If I had to pick, I'd say most of the Flower voters are probably in Group 1. Or some are scum, but are voting Flower because it's a safe vote, and not for any other reason.