"Today I went to the grocery store and bought a few bananas."
"I just got back from the store. I picked up some bananas while I was there."
Both sentences say the same thing. No, they are not completely the same, but neither are the logos in question.
If you want to talk about precise combinations of visual elements, there are LOTS of differences.
Look closely at the logos. The Tox logo makes the person more like a keyhole. The Secure Chat logo uses something more like a natural human silhouette. The ratios of the arc to square are different. The spacing is different. There's a bunch of differences. Frankly, my eye appreciates the the layout and design of the Secure Chat logo... the weights of the Tox logo are a little off... I DO really like the keyhole/person combo, though! So each design has its merits.
The only similarities are the padlock, the chat bubble, and the person.
Just like how in my textual sentences the only similarities are "store", "multiple bananas", and "at some point today".
The point is, the two sentences, one textual and the other visual, both "say the same thing" and are made up of "the same concepts" and "predefined elements of language"... and neither should be considered plagiarism or even that unique to warrant talking about originality...
