Multiple emulsions involve oil drops dispersed inside water drops which are themselves dispersed in an oil continuous phase, labelled as O/W/O or alternatively, water drops in oil drops in an aqueous continuous phase (W/O/W).
A single (or simple) emulsion comprises an aq. phase dispersed in an oil phase (W/O) or vice versa (O/W).
I would give this higher confidence but I've not come across the actual phrase "emulsión compuesta" before but I assume it means "multiple emulsion" (They tend to be formulated by first preparing a simple emulsion (e.g., W/O) and then dispersing it as find drops inside an aq. phase to get the desired multiple emulsion (W/O/W).

Classification[edit]

Macroemulsions can be divided into two main categories based on if they are a single emulsion or a double or multiple emulsion group. Both categories will be described using a typical oil (O) and water (W) immiscible fluid pairing. Single emulsions can be sub divided into two different types. For each single emulsion a single surfactant stabilizing layer exists as a buffer in between the two layers. In (O/W) oil droplets are dispersed in water. On the other hand (W/O) involves water droplets finely dispersed in oil. Double or multiple emulsion classification is similar to single emulsion classification, except the immiscible phases are separated by at least two surfactant thin films. In a (W/O/W) combination, an immiscible oil phase exists between two separate water phases. In contrast, in an (O/W/O) combination the immiscible water phase separates two different oil phases
https://en.wikipedia.org/wiki/Macroemulsion

hope it helps