Model A shows that light has been reflected, whereas Model B shows the light has been refracted. Light will be refracted as the light enters a more dense medium (glass), from a less dense medium (air).
This website has a really useful, thorough explanation for why this occurs:
(Check the explanation under the heading 'Explaining refraction - Higher')
Organisms may play only one role in an ecosystem. ... Each of the organisms in an ecosystem fills the energy role of producer, consumer, or decomposer.
