In Amagi Brilliant Park, the mascot of the titular theme park is a mascot named Moffle.
For anyone who knows Full Metal Panic!, this no doubt bears a strong resemblance to Bonta-kun, the suit that Sosuke designed.
Of course, they don't look exactly the same, but they're similar enough that this is definitely not a coincidence, and viewers are expected to catch this reference.
I know that both Fumoffu and Amagi are animated by Kyoani, based on light novels written by Gatoh Shoji, and directed by Takemoto Yasuhiro. That's already enough to establish a connection between these series, so that this sort of reference isn't out of place.
Is there any in-universe connection between these two series, or is the reference just a throwback to remind viewers of the earlier work and the staff connection between the two?