You guys crack me up.
Ok are you ready. Drum roll please.....................
I don't know.
I must admit I saw the first two pics and that someone had responded sebae and figured I didn't need to look again.
There is some conflicting evidence.
Evidence for BTA:
There seems to be faint rings around the tentacle tips.
I don't recall seeing mags with purple tentacle tips like that.
The anemone hasn't moved to the top of the tank even though lighting is not very bright.
That star shape when it is retracted is a BTA/sebae thing. I haven't seen it in my mag.
Even though the foot is not in a crevice, the thinness of the outer edge and the way that it is stretched looks like a BTA.
Evidence for H. magnifica:
Although BTAs can have red columns, the intensity of the red is more mag-like.
The puckered "lips" of the mouth is a mag thing, but I have seen BTAs like that as well, especially when they are deflated.
Its foot is "perching" on the rock rather than finding a crevice, but it may find a crevice later.
If it has white lines around the mouth, that would make it a BTA, but not all BTAs have the white lines, so it they aren't there, we still won't know.
When I first started writing this I was planning to say I was leaning towards mag, but now after I have lined up all my points, I would say I am leaning BTA.
Bottom line, I don't know. Pictures are a difficult way to make IDs sometimes. If we wait a week it will probably become obvious.