This garden contains more than it seems. You can also find the file in /problems/glory-of-the-garden_3_346e50df4a37bcc4aa5f6e5831604e2a on the shell server.
Solution
Use strings and grep:
$ strings garden.jpg | grep pico
Here is a flag "picoCTF{more_than_m33ts_the_3y35a97d3bB}"
can solve this challenge:
Target completed in 2.29 seconds after 3844 unit cases
strings(/data/targets/garden.jpg) ➜
picoCTF{more_than_m33ts_the_3y35a97d3bB} - (copied)