A classic; perhaps it started the trend of pics or at least gave it a name

This is probably the source of linking the GaoGaiGar 2 robot combining technique name with the ever classic 2 girls squishing breast together pose. Then again Anryu and Kouryu in GaoGaiGar Final probably helped the whole idea along.

A year late on informing you of this, but you would be correct: This image is directly responsible for the name of the "symmetrical_docking" tag.

Also:

http://www.youtube.com/watch?v=GewD05poZ-I&fmt=18

ashot02 said:

Also:

http://www.youtube.com/watch?v=GewD05poZ-I&fmt=18

Sadly, that video is no longer available. Instead, have TenRyuJin's Symmetrical Docking sequence clip (which is this 4koma played straight):

http://www.youtube.com/watch?v=ANpcimIOgac

According to the tweets by Histamine C, RARUSU and Konno Tohiro ([1] [2] [3] [4] [5] [6]), the original manga is on page 148 of this anthology comic, published by Kōdansha in 2003. Tagged the artist.

I can't express how much I thank them.

Skribulous said:

Sadly, that video is no longer available. Instead, have TenRyuJin's Symmetrical Docking sequence clip (which is this 4koma played straight):

http://www.youtube.com/watch?v=ANpcimIOgac

That link's dead too now. Try this one.

Moonspeaker said:

That link's dead too now. Try this one.

That's ChouRyuJin, so here's a working link for TenRyuJin, until it inevitably dies and someone has to post a new one again:

https://www.youtube.com/watch?v=K97Mp9w4LFQ

Artemiy said:

That's ChouRyuJin, so here's a working link for TenRyuJin, until it inevitably dies and someone has to post a new one again:

https://www.youtube.com/watch?v=K97Mp9w4LFQ

Yes, but I believe the original link from ashot02 was ChouRyuJin, and Skribulous just offered a TenRyuJin sequence instead when the first link died. (Admittedly, I can't be sure, as the link was dead by the time I found this post.)