The subcommand of /execute "anchored eyes" affects nbt data of entities

When I use the following command:
"/execute as @p at @s anchored eyes run summon armor_stand ^ ^ ^1

{Small:1b}

"
the armor stand will only be small as soon as it hits the ground, it will be big midair. But if I do the same without "anchored eyes" or even with "anchored feet" the command will work as it is supposed to, meaning that the armor stand will be small midair and on the ground (I only know this example, I don't know if this affects other nbt data as well).