"If you are so inclined, you will be able to read this clue."
Perspective is everything.
Trying a different angle...
(Crujones4433 said Brody may need to have his eyes checked, as he eventually used zoomed-in photos of the clue. But it paid off.) "Under a bench you can see from Grandma's balcony."
"The deck of cards I gave you."
Crujones4433 actually planted this clue weeks in advance.
After some careful arranging...
...the edges of the cards went from this...
(A handy reference line was provided.)
A little bit more googling let Brady know that Liriodendron Tulipfera was a tree, and he knew there was a tree dedicated to him in a nearby park.
Now for a little digging.
According to the original Reddit thread, the check was for $80, which was just enough to put the lucky birthday boy over the top for the scooter he had been saving up for. Great ending, huh?