Applying this to a traffic stop, we'll say A is the seizure of the vehicle and its passengers, B is the search of the vehicle, and C is the search of the driver's person. Since everything in B and C is fine we'll concentrate on A. Let's say the sub-elements in A are (1) reason for stop, (2) behavior during the stop, and (3) length of the stop. The reason for the stop is valid (speeding). The officer's behavior during the stop is polite and concentrates on the ticket. In the first model the officer releases the car and driver after a 15 minute stop. In the second model the officer sits in his car with the driver's license for 55 minutes until a drug dog shows up and is run past the vehicle (40 minutes longer than the ticketing process takes). This aggregation of time is unconstitutional and therefore the seizure of the vehicle and passengers is unconstitutional and therefore the ENTIRETY is unconstitutional.
To be clear, aggregation does not have to be about time. In U.S. v. Edwards the 4th Circuit ruled a search unconstitutional not because the search was without constitutional basis, but because of the aggregated factors of the locale where the search was done and the manner in which it was carried out.
The mosaic theorists claim the aggregation as the entirety and in one sense they are right. It is the entirety in that if it fails the entirety fails too. However, this is true of every constitutionally significant issue and sub-element of that issue. Stating that one sub-element is the whole is nonsensical. To consider it in reverse, if the traffic stop does not aggregate to the point that the seizure of the vehicle and passengers is unconstitutional and therefore A=1, this does not mean that B=1 or C=1.
The mosaic theory is badly flawed. However, aggregation analysis will become more and more important in the modern world. To base 4th Amendment analysis on whether something can be viewed by the world at large is becoming an increasingly poor way to frame things in a world where the phone in your pocket identifies where you are 24 hours a day, your ISP can track your internet activity, and you are required by law to hand over information about yourself to the government and private industry. Unless courts are going to find that the putative "reasonable person" is a guy living in a cabin in the Rockies hand typing his libertarian manifesto, in short order any "reasonable person" will be observable for the vast majority of his life. We must adjust; we just need a better model than the mosaic theory.