I've recently discovered that American Elms in their Toddler Phase look suspiciously like Strawberry Plants in their Toddler Phases, if you don't know how to differentiate their leaves.
I say this, because while it's easy to imagine simply choosing aesthetic oak trees to match yonder username.
It could instead be changed over time following the lifecycle of a plant, from when it's sprout or seedling and cannot be reasonably identified, to it's mighty full grown size.
Your profile picture could be a lootbox that takes years to pay off, depending on how much you're willing to commit to the bit.
Or just a couple weeks, really. It doesn't have to be show accurate growth rates.
There's no Home Owner's Associationon the moon