Our good Israeli friends have been bombing Iranian weapon caches for years --- they've gone in and out of Syria at will. Putin has, for the most part, looked the other way. He only (temporarily) read Israel the riot act when they downed a Russian jet in the process a few years ago.
This is a clear and present escalation on Israel's part; and not the kind easily forgotten by anyone in the region --- or beyond.
It certainly will be seen by Iran as an escalation, but
1. It wasn't the Iranian embassy that was struck.
2. Those killed in the attack were Hezbollah and IRGC, both of which are designated terrorist organizations. They were meeting to facilitate attacks on Israel.
Hezbollah and their sponsor, Iran, would have been wise to avoid attacking Israel when they were engaged in war with Gaza following the Oct 7 attacks. But they jumped in to open a second front to support Hamas. Israel has the right to defend herself, including attacks against Hezbollah in states that provide them sanctuary, and allow attacks from their soil.