Whether you’re modelling or modeling, you’re doing the same thing. The only difference is in the spelling—the one with the single L is preferred in the United States, while the one with two Ls is preferred everywhere else.
If you’re a model, your job is to model clothes made by fashion designers and brands. If someone asks you what you’re doing, you say that you’re modelling—or modeling. If you like to create something but used another piece of work as inspiration, you can say you modeled your work after something. Or you can say you modelled it.
the job of wearing clothes, jewellery, etc. in order to advertise them: