Maybe it is too early to further speculate such panel on 003, after all, it is not on Wuhan mock-up (yet). It is just the artist's wish.
P.S. it is Wuhan not Wuhu.
The cutout for the panel is already on the mock up itself. The proportions of the panel looks very similar to the one on the 055 and ECM tends to be located on the sides of the island based on Liaoning, Shandong, and Kuznetsov.
Just from the location of the panel and its proportions, I have a high confidence of what it is and how it relates to parts from the 055. 003 has its electronics based of the 055's tech, while Shandong is based off the 052D's and the Liaoning from the 052C's. 003 is not going to use the ESM and ECM units you have seen from Shandong and Liaoning based off the island mockup.
Another thing to add, the small tower on top of the island, has panels similar to the one on the top mast of the 055. The six small arrays around the neck might be CEC panels. The four squares above them situated on a crown, might be ESM. Both these are also from the 055. Then you have this stalk, also similar to the one from the 055, which might be an ESM array topped with a TACAN on top. One thing I find missing are the placements for IFF arrays but my guess they would be lining up the top of the island as well as that ridge on top of large S-band arrays.