Dull surprise

This is supposed to be "shock and horror" as a supposedly-under-control Megatron looms menacingly over Lazarus, but in reality... DULL SURPRISE!

"Dull surprise" has become a popular term in the Transformers fandom to sum up the expression range of a character when drawn by Pat Lee (or people who ape his style, like Rob Ruffolo).

The expression in question is a vapid, kind of empty look where you can just hear the character in question just going "Guuuuuuuuuhhhhhhhhhhhhhhhhhhhhhh" while waiting for the next neuron to fire.

The term originated in a skit from Mystery Science Theater 3000's showing of the movie Alien from L.A., where Mike Nelson was playing the "Kathy Ireland Fabulous Range Of Emotions Acting Guessing Game by Hasbro-bro-bro!", in which he had to guess the emotion the supermodel and attempted-actress was portraying in a scene... and the correct answer was invariably "Dull surprise!!".

While the MST3K episode that had the skit in question originally aired in November of 1993, and there's certainly a sizable Transformers/MST3K audience/fan crossover (speaking of dull surprise!!), the term didn't really become a catchphrase in Transformers fandom until the era of Dreamwave comics began in 2002.

A range of emotions from horror and despair to fury and triumph is here summed up by a single slack-jawed facial expression.

A particularly notorious example may be found at the end of Prime Directive, Part 4. Superion has been defeated, and Devastator looms above all the other combatants. Several of them gaze up at him. The Autobots are supposed to be shocked and horrified, Megatron should presumably be elated, and Devastator himself is apparently intended to be roaring in furious triumph. Yet a number of fans were left wondering what everyone was looking at -- had Omega Supreme arrived off-panel? -- since all of their expressions, including Devastator's, were exactly the same.

From Teletraan I: The Transformers Wiki, a Wikia wiki.