Throughout the movie, Malcolm uses 2 different methods to transform his body into Big Momma. One is through the use of a body suit (made of a stuffed cloth material, which is used when Big Momma is wearing a dress) and the other one is through the extensive use of prosthetic makeup (for when Big Momma is showing more skin, at the spa and at the beach). In the beach scene, Malcolm is clearly using the prosthetics when Big Momma is in a one piece bathing suit as much skin is exposed. Big Momma then puts on a big sun dress to cover up (while still wearing the bathing suit and prosthetics). Moments later, she starts chasing Bishop down the beach to the pier. After Bishop jumps off the pier and Malcolm (now with his mask off) looks over the pier, you can see under the big sun dress on his right shoulder that he is wearing the fat suit, not the prosthetics. There was no opportunity for him to have switched from one to the other.
When Big Momma is in front of the Hasidic synagogue, most of the men are all wearing large prayer shawls. In fact, the large shawl is used only during the daytime. The men would only have been wearing small ones.