Two galaxies aligned in a way where their gravity acts as a compound lens

Is it only one direction or does it work the same from the other side?

Should work the other way too. Physics and symmetry:)

Yes in a vague sense. And No in a strong practical sense.

Lensing works in reverse except for time delays which make the idea much more complex. The object's past is projected to us now, but our past would be projected to somewhere that the far object no longer occupies. Double lensing makes this even less reversible.

When the light we are now seeing was emitted, the lensing wasn't in place. In fact, the galaxies doing the lensing hadn't even evolved to the state that we see them in.

So if we sent a response to what we see now, it wouldn't make it back to the lensed objects.

That's just for single lensing. Double lenses are a massive coincidence of events at 4 points in time and space (emission, first deflection, second deflection and observation). That means that light going the other way wouldn't have the two intermediate points in the right place at the right times so it all breaks down for us and the object we see. There are some points that would be double lensed in the reverse direction but the locations and times for the source and observer have only very vague correlation to our location and the location of the object we see.

A simpler answer is just what happens if you look thru a telescope or binoculars "the wrong way" (backwards). The correct way shows a "zoomed in" view of that you're viewing, but looking the wrong way shows a "zoomed out" view.

So lifeforms on the other end of this cosmic "lens[es]" cannot use it to see us better, because in fact it makes us look further away from them than we are, from their perspective.

If only relativity were so simple :)

If I understand right, objects further than a redshift of z ~= 1.8 can't be reached by any signal we emit, and the second galaxy is at a redshift of z = 1.885. But I don't know how precisely (standard deviations rather than decimal places) the distance to the outbound cosmological horizon is being approximated, so it might be reachable by a signal sent by us:

https://upload.wikimedia.org/wikipedia/commons/8/88/Home_in_...

Not sure what the practical analogy would be. You can't use an exploding telescope?

The question I addressed is "does the lensing work the same from the other end". It's a very specific and clear question, and the answer is "no it does not", because if you reverse a telescope lens you get the opposite effect (from zoom-in to zoom-out)

The question of at what distance and relative velocity are the two locations so far apart that light can never make it from one to the other (due to expanding universe) is a completely separate issue.

> Is it only one direction or does it work the same from the other side?

The relationship is (must be) symmetrical. Were this not so, it would violate a principle called "Maxwell's Daemon" (https://en.wikipedia.org/wiki/Maxwell%27s_demon).