As a student, should I offer alternative ways of understanding a point in lectures?
If you are in a small lecture that encourages participation, then it is definitely appropriate to participate, and understanding things in more than one way is often a great thing.  I would recommend phrasing your thoughts as a question rather than a statement, however, e.g.:


  Would I be right in understanding this like [comparison]?


After all, you're only just learning the material and don't yet know if your comparison is actually right!  If you can concerned that you might be talking too much then a) a very good lecturer may be able to let you know gently in the midst of class and b) you can ask the lecturer their opinion after class.