Student or Learner
What is the proper way to use I and me?
example: when pointing at a picture do you say,
This is I.
This is me.
The example you've chosen is one that is depated.
Use "I" when you're the subject.
Use "me" when you're the object.
I use "me" when I'm talking about pictures because I consider it short for "This is [a picture of] me."
Likewise, today we don't say "It is I" in answer to the question "Who is it?" so "This is me" makes more sense and sound better to our ears than "This is I."
Some people argue that any time you have the verb "to be" then the nominative form (I) belongs on "both sides" of the verb (for example, "This is I.") That really doesn't have much foundation in English, so you can feel safe ignoring that argument.
[not a teacher]