Brown put Old Firm rivalry aside as he purposefully walked into the Rangers half during the warm-up ahead of the 1-1 draw at Celtic Park and offered his hand in a show of solidarity with the Finnish midfielder.
The two sides also united ahead of kick-off by refusing to take the knee – the anti-racism tradition adopted before matches this season – as players instead chose to send a message to the football authorities by remaining standing.
"I think it's disgusting what's happened to be perfectly honest," Brown told Sky Sports.
"It doesn't matter whether it's a Rangers player or Celtic player, or whoever it is, it should never be part of the game.
"It just shows that we're with them and stand with them on racism. It's just that little bit of respect towards a fellow professional."
That match ended in a 1-1 draw after Mohamed Elyounoussi's 23rd minute opener for Celtic was cancelled out by Alfredo Morelos' equaliser seven minutes before half-time – his first goal against the Parkhead side in 15 attempts.
Brown believed Celtic should have had the chance to take a 2-0 lead after Odsonne Edouard was booked for simulation by referee Willie Collum following a challenge from Borna Barisic in the box.
"I think in the first half we were exceptional. We could have had three or four and we got a penalty denied as well. It's a stonewaller," he said. "There's no need for Odsonne to go down. He chopped inside and there was contact – we saw it at half-time. It's one of those ones – if you go in 2-0 up at half-time it's a total change of game, but they managed to get back in the game. We had enough chances to win. I thought we were very good today throughout the whole 90 minutes."
Addressing Morelos as 'whoever', Brown added: "[Rangers goal] is a bit unlucky as well because it's probably a foul on Jonjoe. It goes out for a corner, they get a flick-on then 'whoever' scores at the back post as well. It's one of those ones.
"But I think we were miles better than we have been this season. We probably deserved three points as well."
Despite failing to put an end to Rangers’ unbeaten league campaign, Brown insists Celtic still have plenty to play for.
“It's been a hard season for us but again we've came back and been really good the last three games, so it shows you the lads are still fighting and we still have that pride in ourselves as well,” he said.
"We need to keep going. We've got a Scottish Cup to look forward to now and we've got the split as well. We need to make sure we finish the season as high as we possibly can and keep winning games, and just push on as far as we possibly can.
"For the lads now it's playing for next season as well. We don't know what's going to happen in the squad so, whether it's John [Kennedy] that's the new manager, you're playing for your position as well."