It looks like you might be able to bring some of the smaller snow globes home with you from your next trip to see the mouse :D
According to NBC News:
Transportation Security Administration officers will permit the items as long as they are packed in a passenger's plastic, quart-sized, resealable bag along with other gels and liquids.
TSA will permit snow globes "that appear to contain less than 3.4 ounces (of liquid), which is approximately the size of a tennis ball," spokesperson David Castelveter said, "but only if the entire snow globe, including the base, is able to fit in the bag.
"And it has to be the same bag. You don't get a 3-1-1 bag and a snow-globe bag," he added.
Tennis balls will not be used to determine the size and volume of snow globes. Instead, TSA officers will be aware of the size requirement and apply “some discretion in their evaluation of the item being transported,” Castelveter said. As a general rule, he said, if a snow globe is the size of an average fist, it should get through.
The move is part of TSA's ongoing reassessment of its rules, Castelveter said.
The rule is expected to be fully in place by mid-August -- just in time for end-of summer trips to Disneyland, SeaWorld and Busch Gardens.