Osteocephalus deridens — Mocking Bromeliad Treefrog
Some other names for this species:
Mocking Treefrog, Quacking Bromeliad Treefrog
Osteocephalus derides was described by Jungfer et al in this paper in 2000. It's very similar to O. planiceps overall. Dick Bartlett told me that O. deridens has a tympanum about half the size of the eye, whereas O. planiceps has a larger tympanum, so I'm guessing that this one is O. deridens.
Based on the radial pattern in the iris, the relatively small size, and the pattern, I believe this frog is a Osteocephalus deridens. The etymology of this name comes from the original species description: "The specific name is the present participle of the Latin deridere (make fun of someone) in allusion to the males' calls from the treetops that sound as if they are laughing at the collectors' vain attempts to reach them."