You could see it as attending in-absentia, but not the same as attending in person. If you can make it in person go. Make sure to send your guardian angel still.

While very cursory research suggests that the first broadcast television signal was sometime between 1936 and 1941, the option of "live stream" has only really been available since the 1950's for most families, and then only for those in the more economically developed countries.  I recall watching Pope Pius XII's funeral on a black and white television, I would have been 7 years 4 months old at the time.  I doubt the Pre VII church ever ruled on the matter, the medium was so new.  The Post VII church has ruled that "watching or listening over the airwaves or the interweb" rather than attending, DOES NOT fulfill the obligation.  I don't have time to look up a citation, but I have seen this stated.

If one cannot attend Mass for a legitimate reason (illness, distance, lack of transportation, work, and many others) the obligation is dispensed.  If one has questions (or scruples) about this, talk to a priest.  A priest has the authority to dispense from an obligation, random laity on the internet do not.

For an example ... and I am not going to define terms, that would be such a mine field around here ...
If you live across the street from a legitimate / licit / valid Mass (as I said, I'm not defining terms) that was also being live streamed, and you, assuming you are of sound mind and body, just didn't feel like going out, don't like to mingle with people, didn't want to get dressed up, whatever, and watched the Mass rather than attend it ... I'm pretty sure the obligation isn't fulfilled.  On the other hand, if you are stuck in bed in a body cast, or the church is already packed to the rafters and it would be physically impossible to get inside (if only we had more of this situation, provided we were building new and bigger churches) ... the obligation is dispensed.  In the latter case one should still sanctify the day with prayer, and watching the Mass and hearing a good homily on the scriptures would be an excellent way to do that.

I am thinking though, why is this in the anonymous forum?  That seems like a way more legitimate query.